JP3464656B2 - Wireless communication device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital modulation system used for wireless communication.

[0002]

2. Description of the Related Art In a digital mobile radio communication system,
Transmission and reception between the base station device and the communication terminal device are affected by the radio wave propagation environment, and the radio wave propagation environment affects the reception quality and the reception sensitivity characteristic on the receiving side. Therefore, conventionally, as a method for improving the reception sensitivity characteristic of the receiving device by devising the signal point position of the pilot symbol, a method relating to the signal point position of the pilot symbol at the time of performing quasi-coherent detection has been disclosed in the literature (for land mobile communication). 16QAM
Fading distortion compensation method) Sanbe, IEICE Transactions B-II Vol. J-72-B-II N
o. 1 pp. 7-15 January 1989. FIG. 35 shows 1 in the in-phase-quadrature plane (IQ plane).
The signal point arrangement of 6QAM symbols and pilot symbols is shown. In FIG. 35, reference numeral 3501 indicates a 16QAM signal point on the IQ plane, and pilot symbol signal points are indicated by reference numerals 3502, 3503, 3504, and 350.
A method is known in which quasi-coherent detection is performed by using a signal point having the maximum amplitude among 16 QAM signal points as a pilot signal, such as arranging in any one of 5 above.

[0003]

However, in the conventional arrangement of pilot symbols, the signal point having the maximum signal point amplitude of the signal points in one modulation method is set as the signal point of the pilot symbol, but the receiving sensitivity of the receiving apparatus is set. When this is taken into consideration, this point is not always the optimum position as the signal point of the pilot symbol. Further, increasing the transmission power of the transmitting device and increasing the maximum signal point amplitude shown in FIG. 35 in order to improve the receiving sensitivity characteristic of the receiving device,
The transmission power is increased for all the symbols to be transmitted, which is nothing but the increase in the power consumption of the transmission device.

The present invention has been made in view of the above circumstances, and improves the reception sensitivity characteristic of a receiving device by arranging the signal points of pilot symbols while keeping the average transmission power of the transmitting device at a certain level. With the goal.

[0005]

A radio communication apparatus of the present invention has a plurality of signal generating means for generating quadrature baseband signals by different modulation methods, and a signal output from the plurality of signal generating means. Switching means for selecting only the signal, wireless means for performing a predetermined wireless processing on the orthogonal baseband signal selected by the switching means, and power amplification for amplifying the power of the transmission signal output from the wireless means. And the mean transmission output powers of the transmission signals according to the respective modulation methods are equal to each other, and the operating range in the power amplification means becomes a predetermined value,
It adopts a configuration for adjusting the transmission power of symbols for demodulation.

The radio communication apparatus of the present invention has a configuration in which the predetermined value is the same value for each modulation system.

A radio communication apparatus of the present invention selects a plurality of signal generating means for generating quadrature baseband signals by different modulation methods and only a target signal among the signals output from the plurality of signal generating means. The switching device includes a switching device, a wireless device that performs a predetermined wireless process on the orthogonal baseband signal selected by the switching device, and a power amplification device that amplifies the power of the transmission signal output from the wireless device. The transmission power of the symbols for demodulation is adjusted so that the average transmission output powers of the transmission signals according to the respective modulation methods are equal to each other and the reception sensitivity becomes an optimum value.

With these configurations, it is possible to adjust the transmission power of symbols for demodulation while maintaining the average transmission power of the transmission device at a certain level and improve the reception sensitivity characteristic of the reception device. The symbols for demodulation include pilot symbols, unique words, preambles, and the like.

The wireless communication apparatus of the present invention includes a plurality of signal generating means for generating a serial signal by different modulation methods for transmitting digital signals, and a target signal among the serial signals output from the plurality of signal generating means. Switching means for selecting, a serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal, a discrete inverse Fourier transform means for performing a discrete inverse Fourier transform of the serial-parallel converted parallel signal, and a discrete inverse An average transmission output of the transmission signal by each of the modulation methods is provided, which includes a wireless unit that performs a predetermined wireless processing on the Fourier-transformed signal, and a power amplification unit that amplifies the power of the transmission signal output from the wireless unit. The power for demodulation is adjusted so that the powers are equal to each other and the operating range of the power amplification means becomes a predetermined value. Adopt a configuration for adjusting the transmission power of Bol.

The radio communication apparatus of the present invention has a configuration in which the predetermined value is the same value for each modulation method.

The wireless communication apparatus of the present invention includes a plurality of signal generating means for generating serial signals by modulating the transmission digital signals different from each other, and a target signal among the serial signals output from the plurality of signal generating means. Switching means for selecting, a serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal, a discrete inverse Fourier transform means for performing a discrete inverse Fourier transform of the serial-parallel converted parallel signal, and a discrete inverse An average transmission output of the transmission signal by each of the modulation methods is provided, which includes a wireless unit that performs a predetermined wireless processing on the Fourier-transformed signal, and a power amplification unit that amplifies the power of the transmission signal output from the wireless unit. Adjust the transmission power of the symbols for demodulation so that the power is equal to each other and the reception sensitivity is the optimum value. A configuration.

According to these configurations, even in the OFDM system, the transmission power of symbols for demodulation is adjusted while maintaining the average transmission power of the transmission device at a certain level, and the reception sensitivity characteristic of the reception device is improved. be able to.

The radio communication apparatus of the present invention determines the correction value from the ratio of the signal point amplitude of the symbol for demodulation received from any of the above radio communication apparatuses and the maximum signal point amplitude of each modulation method. A configuration is adopted in which a transmission path distortion estimation signal in which distortion due to a transmission path is estimated is multiplied by the correction value to perform detection.

With this configuration, the accuracy of the fading estimation signal can be improved, and the receiving sensitivity characteristic of the receiving device can be improved.

[0015]

[0016]

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[0039]

[0040]

[0041]

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is, in a wireless communication system for performing adaptive modulation, keeping the average transmission output power of the transmitting device at a certain level while maintaining the same phase so that the receiving sensitivity at the receiving device is maximized. -A method in which signal points of pilot symbols are arranged on an orthogonal plane (IQ plane). Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows an example of a frame configuration according to the present embodiment. Hereinafter, the modulation method will be described by taking three kinds of combinations of QPSK, 16QAM, and 64QAM as an example.

In FIG. 1, a preamble 101, a pilot symbol 103, and a unique word 104 are control information, and a preamble 101 includes information on a selected modulation method, QPSK, 16QAM, 64Q.
It includes information indicating either AM. The data symbol 102 contains data information. The pilot symbol 103 is used to estimate the radio wave propagation environment and perform synchronous detection, and the unique word 104 is a signal for the receiving device to time synchronize with the transmitting device. Note that these control information are required to have higher reliability than data symbols.

FIG. 2 shows the configuration of the transmitting apparatus according to this embodiment. In FIG. 2, the QPSK signal generator 201 outputs the orthogonal baseband signal according to the frame configuration of FIG. 1 when the modulation method information included in the control signal is QPSK among the input transmission digital signal and control signal. The generated in-phase component of the QPSK quadrature baseband signal is sent to the in-phase component switching unit 204 as QP
The orthogonal component of the SK orthogonal baseband signal is output to the orthogonal component switching unit 205.

The 16QAM signal generation section 202, when the modulation method information included in the control signal is 16QAM among the input transmission digital signal and control signal, FIG.
The quadrature baseband signal is generated according to the frame configuration of, and the in-phase component of the 16QAM quadrature baseband signal is output to the in-phase component switching unit 204, and the quadrature component of the 16QAM quadrature baseband signal is output to the quadrature component switching unit 205.

In the case of the information 64QAM of the modulation scheme included in the control signal among the input transmission digital signal and control signal, the 64QAM signal generating section 203 generates an orthogonal baseband signal according to the frame configuration of FIG. , The in-phase component of the 64QAM system quadrature baseband signal to the in-phase component switching unit 204, and the quadrature component of the 64QAM system quadrature baseband signal to the quadrature component switching unit 205.
Output to.

The in-phase component switching section 204 includes a QPSK signal generation section 201 or a 16QAM signal generation section 20.
2 or the quadrature baseband signal in-phase component input by the 64QAM signal generation unit 203 and the control signal input from another route, based on the information of the modulation method included in the control signal. The input part is switched so as to input the quadrature baseband signal in-phase component of the modulation method, and the input quadrature baseband signal in-phase component is output to the radio section 206.

The quadrature component switching unit 205 includes a QPSK signal generation unit 201 or a 16QAM signal generation unit 20.
The quadrature baseband signal quadrature component input by either the 2 or 64QAM signal generation unit 203 and the control signal input from a different route, based on the information of the modulation method included in the control signal. The input part is switched so as to input the transmission quadrature baseband signal quadrature component of the modulation method, and the input quadrature baseband signal quadrature component is output to radio section 206.

The radio section 206 includes an in-phase component switching section 20.
The in-phase component of the transmission quadrature baseband signal output from No. 4 and the quadrature component of the transmission quadrature baseband signal output from quadrature component switching unit 205 are subjected to predetermined radio processing and output to transmission power amplification unit 207. The transmission power amplification unit 207 amplifies the signal wirelessly processed by the wireless unit 206 and transmits the amplified transmission signal via the transmission antenna 208.

FIG. 3 shows the configuration of the receiving apparatus according to this embodiment. In FIG. 3, reception radio section 302
Performs a predetermined radio processing on a signal (reception signal) received via the reception antenna 301, and determines a reception quadrature baseband signal in-phase component and a reception quadrature baseband signal quadrature component by a synchronization / modulation scheme determination unit 303 and fading distortion. It outputs to estimation section 304, frequency offset estimation section 305, QPSK detection section 306, 16QAM detection section 307, and 64QAM detection section 308, respectively.

The synchronization / modulation method determination unit 303 detects and detects the unique word 104 in FIG. 1 from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302. The time is synchronized with the transmitting device based on the unique word. Also, the preamble is detected, and the modulation scheme information included in the preamble is identified. The control signal including these two pieces of information is used as a QPSK detection unit 306, 16QAM detection unit 3
07 and 64 QAM detection sections 308 respectively.

Fading distortion estimation section 304 uses the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 302, and the control signal output from synchronization / modulation method determination section 303. Then, the distortion due to fading is estimated from the pilot symbols in FIG.
PSK detection section 306, 16QAM detection section 307, 64Q
It outputs to each of the AM detection units 308.

Frequency offset estimation section 305 uses the received quadrature baseband signal in-phase component and quadrature component output from reception radio section 302, and the control signal output from synchronization / modulation scheme determination section 303, to generate the pilot in FIG. The frequency offset is estimated from the symbol 103, and the frequency offset estimation signal is obtained by the QPSK detection units 306 and 16Q.
It outputs to each of the AM detection unit 307 and the 64QAM detection unit 308.

If the modulation method information contained in the control signal output from the synchronization / modulation method determination section 303 indicates QPSK, the QPSK detection section 306 receives radio section 30.
The fading distortion and frequency offset in the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the fading distortion estimation unit 304,
By using the frequency offset estimation signal output from the frequency offset estimation unit 305, removal and demodulation are performed, and the QPS
K Receive digital signal is output.

The 16QAM detection section 307, when the modulation method information included in the control signal output from the synchronization / modulation method determination section 303 indicates 16QAM, receives the quadrature baseband signal output from the reception radio section 302. Fading distortion and frequency offset in the in-phase component and the reception quadrature baseband signal quadrature component are removed using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Demodulate, 1
Outputs 6QAM received digital signal.

The 64QAM detection section 308 outputs the reception quadrature baseband signal output from the reception radio section 302 when the modulation method information included in the control signal output from the synchronization / modulation method determination section 303 indicates 64QAM. Fading distortion and frequency offset in the in-phase component and the reception quadrature baseband signal quadrature component are removed using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305. , Demodulate, 6
The 4QAM received digital signal 308 is output.

Next, the operations of the transmitting apparatus and the receiving apparatus having the above configurations will be described. First, the transmission digital signal and the control signal shown in FIG.
1, 16QAM signal generation section 202, 64QAM signal generation section 203 is operated, only the signal generation section that matches the modulation method information of the control signal is operated, and the orthogonal baseband signal is generated by the corresponding modulation method signal generation section. Is generated,
Quadrature baseband signal in-phase component in-phase component switching unit 2
In 04, the quadrature baseband signal quadrature component is output to the quadrature component switching unit 205.

The quadrature baseband signal in-phase component output from the modulation method signal generation unit is in-phase component switching unit 204.
Then, it is switched to the input section corresponding to the modulation scheme indicated by the control signal and output to the radio section 206. Further, the quadrature baseband signal quadrature component output from the modulation scheme generation unit is switched by the quadrature component switching unit 205 to the input unit corresponding to the modulation scheme indicated by the control signal, and the radio unit 20.
6 is output.

A radio section 206 performs a predetermined radio processing on the transmission quadrature baseband signal in-phase component output from the in-phase component switching section 204 and the transmission quadrature baseband signal quadrature component output from the quadrature component switching section 205. , And the transmission signal is output to the transmission power amplification unit 207. The transmission signal output from the radio unit 206 is power-amplified by the transmission power amplification unit 207 and transmitted to the reception device via the transmission antenna 208.

The signal transmitted by the transmitter is received by the receiver via the antenna 301 shown in FIG. In FIG. 3, a signal (received signal) received via the antenna 301 is subjected to predetermined radio processing by the reception radio section 302, and the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component are synchronized. Modulation method determination unit 303, fading distortion estimation unit 304, frequency offset estimation unit 305, QPSK detection units 306, 16
The signals are output to the QAM detection unit 307 and the 64QAM detection unit 308, respectively.

The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302 are processed by the synchronization / modulation method determination unit 303.
The unique word 104 shown in FIG. 1 is detected, and time synchronization with the transmission device is established based on the detected unique word 104. Also, the preamble is detected, and the modulation scheme information included in the preamble is identified. A control signal including these two pieces of information is generated, and a fading distortion estimation unit 304, a frequency offset estimation unit 305, a QPS
K detection unit 306, 16QAM detection unit 307, 64QAM
Each is output to the detection unit 308.

The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302, and the control signal output from the synchronization / modulation method determination unit 303 are processed by the fading distortion estimation unit 304. The distortion due to fading is estimated from the pilot symbol 103 shown in FIG. 1, and the fading distortion estimation signal is QPSK detection section 306, 16QAM detection section 307.
It is output to each of the 64QAM detection units 308.

The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 302 and the control signal output from the synchronization / modulation method determination unit 303 are the frequency offset estimation unit 30.
From the pilot symbol 103 shown in FIG.
The frequency offset is estimated, and the frequency offset estimation signal is QPSK detection section 306, 16QAM detection section 307,
It is output to each of the 64QAM detection units 308.

Each detection section corresponding to the modulation method information of the control signal output from the synchronization / modulation method determination section 303, that is, QPSK detection section 306, 16QAM detection section 307, 64.
In the QAM detection section 308, the fading distortion and frequency offset in the reception quadrature baseband signal in-phase component and quadrature component output from the reception radio section 302 are
Removal using the fading distortion estimation signal output from the fading distortion estimation unit 304 and the frequency offset estimation signal output from the frequency offset estimation unit 305
Demodulation is performed, and a received digital signal corresponding to each modulation method is output.

The operation of the transmission power amplifier in the radio communication system of the present embodiment and the signal point arrangement of pilot symbols in each modulation method will be described. In addition,
In the present embodiment, the signal point amplitude of the pilot symbol represents the transmission power on the IQ plane, and increasing the transmission power increases the signal point amplitude of the pilot symbol.

FIG. 4 shows the input / output relationship of the conventional transmission power amplifier. In FIG. 4, reference numeral 401 indicates the operating point of the transmission power amplifier, which is the average transmission output power. Reference numerals 402, 403, and 404 are QPSK, 16QAM, and 64Q, respectively.
It is an operating range of AM (a level range in which a signal input to the power amplifying unit can be input), and indicates an operating range of the transmission power amplifying unit when each modulation method is selected. As shown in FIG. 4, the operating range is largest when the modulation method is 64QAM. As described above, conventionally, the operation range has been determined by the modulation method.

However, the transmission power amplifier is 64 QA.
Since the transmission power amplifier that can linearly amplify the M modulation signal is used, the modulation method is QPSK or 16QAM.
At this time, linear amplification is possible even if the operating range is expanded within a range in which the operating range does not exceed the operating range of 64QAM.

Therefore, in the wireless communication system for performing adaptive modulation according to the present embodiment, the receiving sensitivity characteristic of the receiving device is the highest within the range in which the operating range of the transmission power amplification section does not exceed the operating range of the modulation system. In order to improve, the signal point of the pilot symbol is arranged on the IQ plane. That is, when the modulation method is QPSK or 16QAM, the input level of the pilot symbol is increased within the range where the operating range does not exceed the operating range of 64QAM, and the receiving sensitivity characteristic of the receiving apparatus is improved. Hereinafter, this method will be described.

FIG. 5 shows the arrangement of QPSK symbols and pilot symbol signal points on the IQ plane according to the present embodiment. Reference numeral 501 is a QPSK modulation signal point, and reference numeral 502 is a pilot symbol signal point. Then, the pilot symbol signal point amplitude is r _pilot
Then, if r _pilot is increased, in the receiving device,
The pilot symbol becomes more resistant to noise,
Fading distortion estimation section 304 of the receiving apparatus in FIG.
Since the estimation accuracy of the fading distortion and the estimation accuracy of the frequency offset estimation unit 305 can be improved and highly accurate detection processing can be performed, the reception sensitivity characteristic of the reception device is improved.

FIG. 6 shows the arrangement of 16QAM symbols and pilot symbol signal points on the IQ plane according to this embodiment, and reference numeral 601 indicates 16Q.
AM signal points, reference numeral 602, are pilot symbol signal points. Then, the pilot symbol signal point amplitude is r
When _pilot, in the receiving apparatus and to increase the r _pilot, resistance becomes strong to noise of the pilot symbols, the fading distortion estimator 3 of the receiving apparatus in FIG. 3
Since the estimation accuracy of the fading distortion in 04 and the estimation accuracy of the frequency offset estimation unit 305 are improved and highly accurate detection processing can be performed, the reception sensitivity characteristic of the reception device is improved. The same applies to 64QAM.

Next, the operating ranges of the two types of transmission power amplifiers having different input / output characteristics will be described. FIG. 7 shows the input / output relationship of the two types of transmission power amplification units according to the present embodiment. Here, in order to attempt a general description, the two types of transmission power amplification units are a transmission power amplification unit A and a transmission power amplification unit B. In FIG. 7, reference numeral 701 indicates the input / output relationship of the transmission power amplification unit A, and reference numeral 702 indicates the input / output relationship of the transmission power amplification unit B. When the input level is in the operating range of reference numeral 703, both the transmission power amplification unit A and the transmission power amplification unit B can handle it. However, when the input level is in the operating range of reference numeral 704, there is a range that the transmission power amplifier A cannot handle. For example, in the case of considering a communication device in which a modulation method up to 16QAM can be used, if the use of a transmission power amplification unit having an input / output characteristic of reference numeral 701 can cope with it, it has an input / output characteristic of reference numeral 702. The power consumption can be suppressed to be smaller than that when the transmission power amplifier is used. However, if it is necessary to use the transmission power amplification unit indicated by reference numeral 702 in order to support 64QAM used in the present embodiment, an operation range wider than the operation range indicated by reference numeral 703 should be ensured. You can That is, when applying the QPSK or 16QAM modulation method,
If the transmission power of the pilot symbol is increased within the operation range indicated by reference numeral 704, the accuracy of fading distortion estimation and the accuracy of frequency offset estimation in the receiving apparatus are improved,
The receiving sensitivity characteristic of the receiving device is improved.

In the present embodiment, the operating range of the transmission power amplifying section is the maximum of 64QAM. Therefore,
As a result of making r _pilot larger than r _QPSK , the operating range of the transmission power amplifying section becomes large. However, within the operating range of the 64QAM system, amplification is possible even when QPSK is selected. The same is true for 16QAM.

Considering the above, it becomes possible to establish the input / output relationship of the transmission power amplifier as shown in FIG. FIG. 8 is a diagram showing the input / output relationship of the transmission power amplification unit according to the present embodiment. Reference numeral 801 denotes the operating point of the transmission power amplification unit, and reference numeral 802 denotes the signal point amplitude of the pilot symbol. The operating range of QPSK when the amplitude is larger than the maximum signal point amplitude of conventional QPSK modulation, reference numeral 803 is
16QAM operating range when the signal point amplitude of the pilot symbol is made larger than the maximum signal point amplitude of 16QAM,
Reference numeral 804 is an operating range of the 64QAM system. However, the operating range of reference numeral 802 and the operating range of reference numeral 803 are smaller than the operating range of 64QAM. At this time, as compared with the case where the transmission power amplifier is used as shown in FIG. 4, in FIG.
Although the QAM operating range is wide, amplification is possible and the operating range of each modulation method can be set to the same range. On the other hand, in the receiving device, when QPSK and 16QAM, the noise resistance of the pilot symbol is strong. However, it is not always necessary to increase the amplitude of the pilot symbol, and the fact that there is an optimum amplitude will be described with reference to FIG.

FIG. 9 is a graph showing a pilot symbol and signal point power ratio of QPSK modulation according to the present embodiment, and a desired carrier power to noise power ratio required for bit error rates 10 ⁻⁴ and 10 ^−6. There is. Reference numeral 901 indicates a desired carrier power to noise power ratio required for a bit error rate of 10 ^-4 , and reference numeral 902 indicates a desired carrier power to noise power ratio required for a bit error rate of 10 ^-6 . Focusing on the reference numeral 901, the horizontal axis (r ² _pilot / r ² _QPSK ) of the lowest value of the desired wave power to noise power ratio at the bit error rate of 10 ⁻⁴ is 2 and the amplitude of the pilot signal becomes large. However, the desired carrier power to noise power ratio does not become small. The bit error rate of 10 ⁻⁶ indicated by reference numeral 902 can be considered in the same manner, and it can be said that there is an optimum amplitude of the pilot signal.

Although the single carrier system has been described in this embodiment, the multiplexing system, the CDMA system and the OF system are used.
A DM (Orthogonal Frequency Division Multiplexing) method may be similarly used.

It will be described below with reference to FIG. 10 that it can be applied to common amplification. FIG. 10 shows the configuration of a transmission device that performs common amplification according to this embodiment.
The f1 modulator 1001 digitally modulates the frequency f1 digital signal and adds the frequency f1 transmission signal to the adder 10
Output to 04. The f2 modulator 1002 digitally modulates the frequency f2 digital signal, and outputs the frequency f2 transmission signal to the adder 1004. fn modulator 1003
Digitally modulates the digital signal for frequency fn,
The transmission signal of frequency fn is output to addition section 1004.

Adder 1004 adds the transmission signal of frequency f1, the transmission signal of frequency f2, and the transmission signal of frequency fn, and outputs the added transmission signal to transmission power amplifier 1005. The transmission power amplification unit 1005 amplifies the added transmission signal and transmits the amplified transmission signal to the transmission antenna 100.
Send via 6.

As described above, according to the present embodiment, in the wireless communication system for performing adaptive modulation, the IQ is set so as to maximize the receiving sensitivity of the receiving device while keeping the average transmitting output power of the transmitting device constant. By arranging the signal points of the pilot symbols on the plane, it is possible to improve the reception sensitivity characteristic of the receiving device.

The modulation methods are QPSK, 16QAM,
Although description has been made by taking three types of combinations of 64QAM as an example, the present invention is not limited to this modulation system, and is not limited to switching of three types of modulation systems.

In this embodiment, signal points known as pilot symbols have been described as an example, but the present invention is not limited to this, and for example, PSK modulated signals may be used as pilot symbols.

In this embodiment, pilot symbols are used for fading distortion estimation and frequency offset estimation in the receiving apparatus, but it is also possible to use other control information such as the preamble and unique word in FIG. is there.

Then, with respect to the control information, which is an example of the channel control information excluding the data, it is possible to carry out the same operation as the pilot symbol in the present embodiment. At this time, the control information, compared with the data in particular, has a characteristic of being error-resistant to noise.

(Embodiment 2) In Embodiment 2, in the radio communication system, the transmitter and the receiver using the method described in Embodiment 1, the communication method for switching the modulation method depending on the radio wave propagation environment and communication traffic. The modulation method deciding method will be described.

FIG. 11 is a diagram showing an example of a frame structure transmitted by the communication terminal according to the present embodiment. In FIG. 11, the same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 11, reference numeral 1101 is a preamble and includes control information. Reference numeral 1102 is radio wave propagation environment estimation information, which is a symbol for the communication terminal to estimate the radio wave propagation environment of the signal transmitted by the base station and notify the base station as radio wave propagation environment information.

Next, the configuration of the receiving device of the base station will be described. FIG. 12 shows the configuration of the receiving apparatus of the base station according to this embodiment. In FIG. 12, the reception wireless unit 1
202 performs predetermined radio processing on a signal (reception signal) received via antenna 1201 and outputs a reception quadrature baseband signal in-phase component and a reception quadrature baseband signal quadrature component to synchronization section 1203 and detection section 1204. .

The synchronization unit 1203 detects the unique word 104 in FIG. 11 from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 1202, and the detected unique word 104. Based on the above, time synchronization with the communication terminal is established, and a synchronization signal is output to the detection unit 1204.

Detection section 1204 converts the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 1202, and the synchronization signal output from synchronization section 1203 into a signal transmitted by the communication terminal. The detection processing is performed and the received digital signal is detected by the data detection unit 1
Output to 205.

The data detection unit 1205 has a detection unit 1204.
The radio wave propagation environment information is output to the transmission data generation unit 1206 based on the frame configuration of FIG. 11 from the received digital signal output from the output digital signal, and the reception data is output.

The transmission data generation unit 1206 determines the modulation method based on the radio wave propagation environment information from the radio wave propagation environment information output from the data detection unit 1205 and the input transmission data, and according to the determined modulation method. And a control signal for notifying the base station of the determined modulation method. When the data detection unit 1205 determines that there are a plurality of incoming waves, the transmission data generation unit 1206 does not receive the influence of another parameter indicating the radio wave propagation environment, and the transmission data generation unit 1206 outputs a Q having a strong error tolerance.
Select PSK and request to the communication terminal. This is to prevent this when the receiving device cannot demodulate this signal when a plurality of incoming waves are received.

FIG. 13 shows an example of a frame structure transmitted by the base station according to this embodiment. Note that FIG.
11 that are the same as those in FIG.
Detailed explanation is omitted. In FIG. 13, reference numeral 1301 denotes modulation method information, which is a symbol for notifying the communication terminal of the modulation method of the base station.

Next, the configuration of the transmission device of the communication terminal device will be described. FIG. 14 shows the configuration of the transmission device of the communication terminal according to the present embodiment. 14, a transmission data generation unit 1401 generates a transmission digital signal according to the frame configuration of FIG. 11 from the transmission data and the radio wave propagation environment estimation signal, and outputs it to the orthogonal baseband signal generation unit 1402.

The orthogonal baseband signal generator 1402 is
A transmission quadrature baseband signal in-phase component and a transmission quadrature baseband signal quadrature component are generated from the transmission digital signal output from the transmission data generation unit 1401 and output to the transmission wireless unit 1403.

Transmission radio section 1403 performs predetermined radio processing on the transmission quadrature baseband signal in-phase component and transmission quadrature baseband signal quadrature component generated by transmission quadrature baseband signal generation section 1402, and amplifies the transmission signal to transmit power. It is output to the unit 1404. Transmission power amplifier 1404
Amplifies the transmission signal output from the transmission radio unit 1403, and outputs the amplified transmission signal to the base station via the transmission antenna 1405.

FIG. 15 shows the configuration of the receiving apparatus in the communication terminal according to this embodiment. In FIG.
Reception radio section 1502 performs a predetermined radio reception process on a signal (reception signal) received via reception antenna 1501, and outputs a reception quadrature baseband signal in-phase component and a reception quadrature baseband signal quadrature component.

The synchronization / modulation method determination unit 1506 uses the received word quadrature baseband signal in-phase component and the received quadrature baseband signal quadrature component output from the reception radio unit 1502 to generate a unique word of the frame structure transmitted by the base station shown in FIG. 104, the time synchronization with the base station is performed, the modulation method information 1301 is detected, the modulation method is estimated, and the synchronization signal and the modulation method information are output to each modulation method detection unit.

When the modulation method information indicates QPSK, the QPSK detection section 1503 demodulates the received quadrature baseband signal in-phase component, the reception quadrature baseband signal, the synchronization signal, and the modulation method information, and QPSK-detects the received digital signal. Output a signal.

The 16QAM detection section 1504 demodulates from the reception quadrature baseband signal in-phase component, the reception quadrature baseband signal, the synchronization signal and the modulation scheme information, when the modulation scheme information indicates 16QAM, demodulates the 16QAM-detected reception digital signal. Output a signal.

When the modulation method information indicates 64QAM, the 64QAM detection section 1505 demodulates the received quadrature baseband signal in-phase component, the reception quadrature baseband signal, the synchronization signal, and the modulation method information, and receives the 64QAM-detected received digital signal. Output a signal.

Interference wave strength estimating section 1507 selects, from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 1502,
The strength of the interference wave is estimated from the modulated signal, the unique word or the pilot symbol, and the interference wave strength estimation signal is output to the radio wave propagation environment estimation unit 1511.

The electric field strength estimating unit 1508 has the receiving radio unit 1
Of the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from 502, the received electric field strength or the carrier power to noise power ratio is estimated from the modulated signal, the unique word or the pilot symbol,
The electric field strength estimation signal is output to the radio wave propagation environment estimation unit 1511.

Multipath estimating section 1509 selects from among the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 1502.
The multipath condition is estimated from the modulated signal, the unique word or the pilot symbol, and the multipath estimation signal is output to the radio wave propagation environment estimation unit 1511.

Doppler frequency estimating section 1510 estimates the Doppler frequency from the modulated signal, the unique word or the pilot symbol among the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal output from reception radio section 1502, and performs the Doppler frequency estimation. The frequency estimation signal is output to the radio wave propagation environment estimation unit 1511.

The radio wave propagation environment estimation unit 1511 has an interference wave strength estimation signal, an electric field strength estimation signal, a multipath estimation signal,
From the Doppler frequency estimation signal, for example, when the electric field strength is weak, when the Doppler frequency is high, when there are multiple incoming waves, and when the interfering wave strength is strong, QPSK is selected. And output. When the multipath estimation unit 1509 determines that there are a plurality of incoming waves, the multipath estimation unit 1509 is not affected by other parameters indicating the radio wave propagation environment.
511 selects a modulation method with strong error tolerance (QPSK in this embodiment) and requests the communication terminal. This is because when a plurality of incoming waves are received, the receiving device cannot demodulate the signals, so that this is prevented. Alternatively, the radio wave propagation environment estimation unit 1511 may output the interference wave estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself.

Next, operations of the base station and the communication terminal having the above configurations will be described. First, in the transmitter of the communication terminal shown in FIG. 14, the transmission data and the radio wave propagation environment estimation signal are generated by the transmission data generation unit 1401 as a transmission digital signal according to the frame configuration of FIG. 11, and orthogonal baseband signal generation is performed. It is output to the section 1402.

The transmission digital signal output from the transmission data generation unit 1401 is the orthogonal baseband signal generation unit 14
02, it is generated as a transmission quadrature baseband signal in-phase component and a transmission quadrature baseband signal quadrature component, and output to the transmission radio section 1403.

The orthogonal component of the quadrature baseband signal and the quadrature component of the quadrature baseband signal output from the quadrature baseband signal generator 1402 are transmitted by the transmission radio unit 1403.
Predetermined wireless processing is performed, and the transmission signal is transmitted by the transmission power amplification unit 1.
It is output to 404.

The transmission signal subjected to the predetermined radio processing by the transmission radio section is power-amplified by the transmission power amplification section 1404 and transmitted via the transmission antenna 1405.

The signal transmitted by the communication terminal is shown in FIG.
It is received by the base station shown in. In FIG. 12, the signal (received signal) received via the receiving antenna 1201 is
A predetermined radio processing is performed in radio section 1202, and the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component are output to synchronization section 1203 and detection section 1204.

A unique word is detected by the synchronizing section 1203 between the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 1202, and a unique word is detected by the communication terminal based on the detected unique word. Are synchronized with each other, a synchronization signal is generated, and output to the detection unit 1204.

The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 1202 are detected by the detection section 1204 by the synchronization section 12.
Detection processing is performed based on the synchronization signal output from 03, and the received digital signal is output to the data detection unit 1205.

The data detection section 1205 generates radio wave propagation environment information from the received digital signal output from the detection section 1204, and outputs it to the transmission data generation section 1206. Also, the received data is output.

According to the radio wave propagation environment, the radio wave propagation environment information output from the data detection unit 1205 may include a plurality of incoming waves depending on the radio wave propagation environment, for example, when the electric field strength is weak, the Doppler frequency is high, and the like. If there is
When the intensity of the interfering wave is strong, QPSK is selected, so that the modulation method is determined, the transmission data is modulated by the modulation method, and the transmission digital signal is output. Further, the control signal modulated by the determined modulation method is output.

Next, the signal transmitted from the transmitter of the base station (referring to FIG. 1) is received by the receiver of the communication terminal shown in FIG. In FIG. 15, a receiving antenna 1501
The signal (received signal) received via the reception wireless unit 1
In 502, a predetermined reception process is performed, and the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component are subjected to an interference wave strength estimation unit 1507, an electric field strength estimation unit 1508, a multipath estimation unit 1509, a Doppler frequency estimation unit. 1510, QPSK detector 1503, 16QA
M detection section 1504, 64QAM detection section 1505, synchronization /
It is output to the modulation method determination unit 1506.

A unique word is detected in the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 1502 by the synchronization / modulation method determination section 1506, and based on the detected unique word. The time is synchronized with the base station. Also,
The modulation method information is detected, the modulation method is estimated, and the synchronization signal and the modulation method information are output to each modulation method detection unit.

The reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 1502 are synchronized and synchronized in each modulation method detection section.
Based on the synchronization signal and modulation method information output from the modulation method determination unit 1506, demodulation is performed and the corresponding received digital signal is output.

For the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 1502, parameters for estimating the propagation environment are estimated in each estimation section, and the estimated signal is the radio wave propagation environment. It is output to the estimation unit 1511.

The estimated signals output from the respective estimation units are comprehensively determined by the radio wave propagation environment estimation unit 1511, and the radio wave propagation environment information to be notified to the base station is estimated and output.

Next, the modulation method selected in the initial stage of the transmission signal transmitted by the base station will be described. For example, when the wireless communication system as in this embodiment is constructed, the modulation method used at the initial stage of the transmission signal transmitted by the base station becomes a problem. In this case, since the base station has never transmitted a transmission signal to the communication terminal, the communication terminal cannot estimate the radio wave propagation environment. Therefore, the base station
It is necessary for the own station to decide the modulation method to be adopted at the initial stage. For example, if 16QAM or 64QAM is used as the initial modulation method, the data quality cannot be obtained at the communication terminal when the radio wave propagation environment is bad. Considering this, it is better to select QPSK modulation.

As described above, by setting the modulation method selected initially as the most resistant to noise among the switchable modulation methods, the communication terminal
Data quality will be improved. The initial setting of this modulation method is not limited to this embodiment, but can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

Similarly, in the communication system characterized by changing the error correction system depending on the radio wave propagation environment, the initial error correction system of the transmission signal to be transmitted can be similarly considered. The error correction method initially selected is the error correction method having the highest error correction ability among the switchable error correction methods, so that the data quality is improved. This initial setting of the error correction method is not limited to this embodiment, but can be applied to a communication method characterized by switching the error correction method depending on the radio wave propagation environment, communication traffic, and the like.

When the modulation method is variable, it is assumed that the base station is always transmitting the preamble 1101, the unique word 104, and the pilot symbol 103 excluding the data symbol 102 in FIG. The communication terminal uses these signals transmitted by the base station to estimate the radio wave propagation environment, and when starting communication with the base station, transmits information on the radio wave propagation environment to the base station, and the base station is Data quality can be obtained by determining the initial modulation method of the data symbol 102 based on the information on the radio wave propagation environment transmitted from the communication terminal. At this time, information on the modulation method can be included in the radio wave propagation environment information. The initial setting of the modulation method by this method is not limited to this embodiment, but can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like. Moreover, although the preamble, unique word, and pilot symbol have been described as signals that are constantly transmitted, the present invention is not limited to this, and a dedicated symbol for estimating the radio wave propagation environment may be inserted.

Similarly, for example, in a communication system characterized by changing the error correction system depending on the radio wave propagation environment, the initial error correction system of the transmission signal to be transmitted can be considered in the same manner. When estimating the radio wave propagation environment from the signal that is constantly transmitted and starting communication with the base station, the radio wave propagation environment information is transmitted to the base station, and the base station is the radio wave propagation environment information transmitted from the communication terminal. Data quality can be obtained by determining the error correction method of the data symbol based on At this time, the information of the error correction method can be included in the radio wave propagation environment information. The initial setting of the modulation method by this method is not limited to this embodiment, but can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

As described above, it is possible to configure the wireless communication system, the transmitting device, and the receiving device using the method described in the first embodiment, thereby improving the receiving sensitivity characteristic of the receiving device. Becomes At this time, three types of combinations of QPSK, 16QAM, and 64QAM have been described as the modulation systems, but the present invention is not limited to this, and is not limited to switching of three types of modulation systems. Further, in FIG. 2 and FIG. 12, for example, the information of communication traffic may be input, and the modulation method may be determined in consideration of this. Further, as the parameters of the radio wave propagation environment, the interference wave strength, the electric field strength, the multipath condition, and the Doppler frequency have been described as examples, but the parameters are not limited to these.

(Third Embodiment) In the third embodiment, a CD is used.
In the MA method, an initial setting and a setting method when the modulation method of each channel adaptively changes the modulation method depending on the radio wave propagation environment, communication traffic, etc. will be described. At this time, the primary modulation (data modulation) of the base station is a communication method capable of switching between QPSK modulation, 16QAM, and 64QAM depending on the radio wave propagation environment, communication traffic, and the like.

FIG. 16 shows an example of the frame structure of a signal transmitted by the base station in the CDMA system according to this embodiment. The frame of the control channel is channel A.
Of modulation method information 1601, channel A transmission power control information 1602, channel Z modulation method information 1603, channel Z transmission power control information 1604, and the like.
The channel A frame structure is composed of channel A data symbols 1605, and the primary modulation of channel A data symbols 1605 is QPSK, 16QAM, 64Q.
It is assumed that any of the AM modulation methods is adopted. The channel Z frame structure is the channel Z data symbol 1606.
Channel Z data symbol 160
The primary modulation of No. 6 adopts any one of QPSK, 16QAM, and 64QAM.

FIG. 17 shows the configuration of the transmitting apparatus of the base station in the CDMA system according to this embodiment. The spread spectrum modulation section 1701 of channel A performs QPSK modulation on the transmission digital signal of channel A based on the modulation scheme information of channel A among the input transmission digital signal of channel A and the modulation scheme information of channel A.
Performs primary modulation of either 16QAM or 64QAM,
Adder 170 adds the transmission quadrature baseband signal of channel A
Output to 3.

Spread spectrum modulator 170 for channel Z
Reference numeral 2 is a primary modulation of any one of QPSK modulation, 16QAM, and 64QAM for the transmission digital signal of channel Z, based on the modulation scheme information of channel Z of the input transmission digital signal of channel Z and the modulation scheme information of channel Z. And outputs the transmission quadrature baseband signal of channel Z to addition section 1703.

Addition section 1703 receives the input transmission quadrature baseband signal of the pilot channel, the transmission quadrature baseband signal of the control channel, the transmission quadrature baseband signal output from spread spectrum modulation section 1701 of channel A, and the transmission channel of the channel Z. The transmission quadrature baseband signals output from spread spectrum modulation section 1702 are added, and the added transmission quadrature baseband signals are output to transmission radio section 1704.

Radio transmitting section 1704 performs predetermined radio processing on the transmission quadrature baseband signal after addition output from adding section 1703, and outputs a transmission signal.

The transmission power amplification section 1705 has the transmission radio section 1
The transmission signal output from 704 is amplified, and the amplified transmission signal is output via the antenna 1706.

FIG. 18 shows the configuration of the receiving apparatus of the base station in the CDMA system according to this embodiment. Reception radio section 1802 performs predetermined radio processing on a signal (reception signal) received via antenna 1801, and outputs a reception quadrature baseband signal to channel A detection section 1803 and channel Z detection section 1804.

Channel A detection section 1803 performs detection processing on the reception quadrature baseband signal output from reception radio section 1802 and outputs the reception digital signal of channel A to channel A data detection section 1805. The channel Z detection unit 1804 also performs detection processing on the reception quadrature baseband signal output from the reception wireless unit 1802, and outputs the reception digital signal of channel Z to the channel Z data detection unit 1806.

The channel A data detection unit 1805 generates radio wave propagation environment information estimated by the communication terminal of channel A from the received digital signal of channel A output from the channel A detection unit 1803, and the channel A modulation method determination unit Output to 1807. It also outputs the reception data of channel A.

The channel Z data detection unit 1806 generates radio wave propagation environment information estimated by the communication terminal of channel Z from the received digital signal of channel Z output from the channel Z detection unit 1804, and the channel Z modulation method determination unit Output to 1808. It also outputs the reception data of channel Z.

The channel A modulation method determination unit 1807 determines the data quality and data of the communication terminal of the channel A from the input communication traffic information and the radio wave propagation environment information of the channel A output from the channel A data detection unit 1805. QPSK, 16QA as the modulation method compatible with transmission speed
It is selected from M and 64 QAM and is output to the control channel transmission signal generation section 1809 as the modulation method information of channel A.

The channel Z modulation method determination unit 1808 determines the data quality and data of the communication terminal of the channel Z from the input communication traffic information and the radio wave propagation environment information of the channel Z output from the channel Z data detection unit 1806. QPSK, 16QA as the modulation method compatible with transmission speed
It is selected from M and 64 QAM and is output to the control channel transmission signal generation unit 1809 as the modulation method information of the channel Z.

The control channel transmission signal generation section 1809 is
The channel A modulation method information is output using the channel A modulation method information output from the channel A modulation method determining section 1807 and the channel Z modulation method information output from the channel Z modulation method determining section 1808. A control channel signal based on the control channel frame structure of FIG. 16 including the system information is generated and output.

FIG. 19 shows an example of the frame structure of a signal transmitted by a communication terminal in the CDMA system according to this embodiment. Reference numeral 1901 indicates the radio wave propagation environment of the signal transmitted from the base station. This is radio wave propagation environment information for the terminal to estimate and notify the base station. Reference number 1
902 is a data symbol.

FIG. 20 shows the configuration of the transmitting apparatus of the communication terminal in the CDMA system according to this embodiment. Transmission data generating section 2001 uses the transmission digital signal and the radio wave propagation environment estimation signal as input to transmit digital signals. A signal is generated and output to the spread spectrum modulator 2002.

The spread spectrum modulation section 2002 spreads the transmission digital signal output from the transmission data generation section 2001 and outputs the transmission quadrature baseband signal according to the frame configuration of FIG. 23 to the transmission radio section 2003.

The transmission radio section 2003 performs a predetermined radio processing on the transmission quadrature baseband signal output from the spread spectrum modulation section 2002, and outputs the transmission signal to the transmission power amplification section 2.
Output to 004.

The transmission power amplifying section 2004 has the transmission radio section 2
The transmission signal output from 003 is amplified, and the amplified transmission signal is transmitted via the antenna 2005.

FIG. 21 shows the configuration of the receiving apparatus of the communication terminal in the CDMA system according to this embodiment. In FIG. 21, a signal (received signal) received via the receiving antenna 2101 is received by the receiving radio unit 2102.
Predetermined reception processing is performed, and the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component are output to the interference wave strength estimation unit 2104, the electric field strength estimation unit 2105, the multipath estimation unit 2106, and the Doppler frequency estimation 2107. .

The detection unit 2103 performs detection processing on the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 2102,
Output.

Interference wave intensity estimating section 2104 has the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2102.
The interference wave intensity is estimated from the pilot channel component and the control channel component, and the interference wave intensity estimation signal is output to the radio wave propagation environment estimation unit 2108.

The electric field strength estimating section 2105 has a reception radio section 2
Of the received quadrature baseband signal in-phase component and the received quadrature baseband signal quadrature component output from 102, the received electric field strength is estimated from the pilot channel component and the control channel component, and the electric field strength estimation signal is estimated as the radio wave propagation environment. It is output to the unit 2108.

Multipath estimating section 2106 has the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2102.
The multipath condition is estimated from the pilot channel component and the control channel component, and the multipath estimation signal is output to the radio wave propagation environment estimation unit 2108.

Doppler frequency estimating section 2107 determines the Doppler frequency from the pilot channel component and the control channel component of the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2102. Estimate and output the Doppler frequency estimation signal to the radio wave propagation environment estimation unit 2108.

As described above, by inserting the information of the modulation scheme transmitted by the base station into the control channel, the base station can transmit the modulation scheme of the transmission signal transmitted to the communication terminal. Is. Further, in particular, the communication terminal adopts a method of estimating the radio wave propagation environment by using the pilot channel and the control channel transmitted from the base station, so that the base station can transmit data symbols to the communication terminal even when the base station does not transmit data symbols. The communication terminal can estimate the radio wave propagation environment.

By taking the above means, CDMA
In the system, the modulation method of each channel is the radio wave propagation environment,
It is possible to configure a wireless communication system in which the modulation system is switched according to communication traffic and the like. Similarly, it is possible to configure a wireless communication system in which the error correction method of each channel is variable according to the radio wave propagation environment, communication traffic, and the like.

Next, in the CDMA system, a method of initializing a modulation system in which the modulation system of each channel is variable depending on the radio wave propagation environment, communication traffic, etc. will be described. For example, when the wireless communication system as in this embodiment is constructed, the modulation method used at the initial stage of the transmission signal transmitted by the base station becomes a problem. In this case, for example, 16QAM
Alternatively, if 64QAM is used as the initial modulation method, the data quality cannot be obtained at the communication terminal when the radio wave propagation environment is bad. Considering this, Q
It would be better to select PSK modulation.

As described above, the data quality is improved in the communication terminal by setting the modulation system selected initially as the most resistant to noise among the switchable modulation systems. become.

Similarly, for example, in a communication system in which the error correction system of each channel is variable depending on the radio wave propagation environment, communication traffic, etc., the initial error correction system of the transmission signal to be transmitted is considered in the same way, and is initially selected. By adopting the error correction method having the highest error correction capability among the switchable error correction methods, the quality of data is improved.

In the CDMA system, an initial setting method when the modulation system of each channel is switched according to the radio wave propagation environment, communication traffic, etc. will be described. In this method, the communication terminal is constantly transmitting data from the base station even when it is not communicating data with the base station. For example, the radio wave propagation environment is estimated from the signals of the pilot channel and the control channel. Then, when the communication terminal starts data communication with the base station, the communication terminal first transmits the radio wave propagation environment information estimated from the signals of the pilot channel and the control channel to the base station, and the base station transmits the radio wave propagation environment information. After receiving the signal, it is said that QPSK is selected as the modulation method of the transmission signal transmitted by the base station, for example, when the electric field strength is weak, the Doppler frequency is high, a plurality of incoming waves are present, or the interfering wave strength is strong. To decide. As described above, in the communication terminal, the quality of the initial data transmitted by the base station is improved.

Similarly, for example, the modulation method of each channel can be applied to a communication method in which the error correction method is variable depending on the radio wave propagation environment, communication traffic, and the like. The communication terminal estimates the radio wave propagation environment from the pilot channel and the control channel that the base station is constantly transmitting, and when starting communication with the base station, transmits information on the radio wave propagation environment to the base station, and the base station is Based on the information on the radio wave propagation environment transmitted from the communication terminal, for example, when the electric field strength is weak, when the Doppler frequency is high, when there are multiple incoming waves,
The data quality can be obtained by determining the error correction method of the data symbol such that the method having a strong error correction capability is selected when the interference wave intensity is strong. However, in the description of the CDMA system, the pilot channel and the control channel have been described as an example of the signal that is constantly transmitted, but the present invention is not limited to this, and a signal that is always transmitting may be used. Also, the modulation method of the transmission signal transmitted by the base station has been described as variable, but the present invention is not limited to this, and the modulation method of the transmission signal transmitted by the communication terminal may be variable.

As described above, it is possible to configure the wireless communication system, the transmitting device, and the receiving device using the method described in the first embodiment, and thereby it is possible to improve the receiving sensitivity characteristic of the receiving device. Becomes At this time, three types of combinations of QPSK, 16QAM, and 64QAM have been described as the modulation systems, but the present invention is not limited to this, and is not limited to switching of three types of modulation systems. Further, in FIG. 2 and FIG. 12, for example, the information of communication traffic may be input, and the modulation method may be determined in consideration of this. Further, as the parameters of the radio wave propagation environment, the interference wave strength, the electric field strength, the multipath condition, and the Doppler frequency have been described as examples, but the parameters are not limited to these.

(Embodiment 4) In Embodiment 4, a radio communication system, a transmitting apparatus, and a receiving apparatus using the method described in Embodiment 1 will be described.

The configuration of the transmitting apparatus of the base station according to the present embodiment employs FIG. 1, and detailed description thereof will be omitted. FIG. 22 shows the configuration of the receiving apparatus of the base station according to this embodiment. The reception wireless unit 2202 has an antenna 2201.
Predetermined radio processing is performed on the signal received via, and a reception quadrature baseband signal in-phase component and a reception quadrature baseband signal quadrature component are output.

The synchronizing section 2203 establishes time synchronization with the communication terminal based on the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio section 2202, and the detection section 2204 as a synchronization signal.
Output to.

The detection unit 2204 performs detection processing from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from the reception radio unit 2202, and the synchronization signal output from the synchronization unit 2203, and performs reception processing. Output a signal.

Interference wave intensity estimating section 2205 estimates the interference wave intensity from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2202, and modulates the interference wave intensity estimation signal. It is output to the method determination unit 2209.

The electric field strength estimating section 2206 is connected to the receiving radio section 2
The electric field strength is estimated from the received quadrature baseband signal in-phase component and the received quadrature baseband signal quadrature component output from 202, and the electric field strength estimation signal is modulated by the modulation scheme determination unit 22.
It outputs to 09.

Multipath estimating section 2207 estimates the multipath situation from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2202 and modulates the multipath estimation signal. It is output to the determination unit 2209.

Doppler frequency estimating section 2208 estimates the Doppler frequency from the reception quadrature baseband signal in-phase component and the reception quadrature baseband signal quadrature component output from reception radio section 2202, and the Doppler frequency estimation signal is used as a modulation scheme determining section. It is output to 2209.

Modulation method determining section 2209 determines the base station based on the interference wave strength estimation signal, electric field strength estimation signal, multipath estimation signal and Doppler frequency estimation signal obtained based on the signal transmitted by the communication terminal. Determines the modulation method of the signal transmitted by, for example, when the electric field strength is weak, when the Doppler frequency is high, when there are multiple incoming waves, and when the interfering wave strength is strong, QPSK is selected, and the control signal is selected. Output.

Next, the modulation method selected in the initial stage of the transmission signal transmitted by the base station will be described. For example, when the wireless communication system as in this embodiment is constructed, first, the communication terminal transmits the transmission signal, and the base station receives the transmission signal transmitted by the communication terminal to estimate the radio wave propagation environment. For example, when the electric field strength is weak, the Doppler frequency is high, there are a plurality of incoming waves, and when the interfering wave strength is strong, QPSK is selected. Thus, by determining the initial modulation method, the data quality is improved in the communication terminal. The initial setting of this modulation method is not limited to this embodiment, but can be applied to a communication method characterized by switching the modulation method depending on the radio wave propagation environment, communication traffic, and the like.

Similarly, for example, in the communication system characterized by changing the error correction system depending on the radio wave propagation environment, the initial error correction system of the transmission signal to be transmitted can be considered in the same manner, and the error correction selected in the initial stage can be considered. First, a communication terminal transmits a transmission signal.For example, when the electric field strength is weak, the Doppler frequency is high, a plurality of incoming waves are present, or when the interfering wave strength is strong, the error correction capability is strong. The base station may receive the transmission signal transmitted by the communication terminal, estimate the radio wave propagation environment, determine the error correction method, and determine the error correction method of the signal transmitted by the base station.

As described above, the data quality is improved in the communication terminal by determining the initial error correction method. This initial setting of the error correction method is not limited to this embodiment, but can be applied to a communication method characterized by switching the error correction method depending on the radio wave propagation environment, communication traffic, and the like.

As described above, it is possible to configure the wireless communication system, the transmitting device and the receiving device using the method described in the first embodiment, thereby improving the receiving sensitivity characteristic of the receiving device. It will be possible. Also, in FIG.
In FIG. 22, for example, communication traffic information may be input, and the modulation method may be determined in consideration of this. Also,
As the parameters of the radio wave propagation environment, the interference wave strength, the electric field strength, the multipath condition, and the Doppler frequency have been described as examples, but the parameters are not limited to these.

In this embodiment, regardless of the multiplexing method,
You may implement similarly by a CDMA system and an OFDM system.

(Embodiment 5) In Embodiment 5, the configurations of a transmitter and a receiver of the wireless communication system of the present invention will be described.

FIG. 23 shows an example of the frame structure according to the present embodiment, and the reference numeral 23 with respect to the horizontal axis time.
Reference numeral 01 is a preamble, which is a symbol for the receiving device to synchronize with the transmitting device in time. Reference numeral 2302 is a data symbol, and the modulation method is variable. Reference numeral 2303 is a pilot symbol, which is a symbol for estimating transmission path distortion and frequency offset. Reference numeral 2304 is a control symbol and is a symbol for system control such as system information and cell information.

FIG. 24 shows the signal point arrangement of QPSK symbols and pilot symbols on the IQ plane according to the present embodiment. Reference numeral 2401 is the signal point of data symbol 2302 in FIG. 23 and reference numeral 2402 is the preamble. Reference numeral 2301 denotes a signal point of the control symbol 2304, and reference numeral 2403 denotes a signal point of the pilot symbol 2303. Reference numerals 2402 and 24
The signal point amplitude of 03, that is, the distance from the origin is larger than the signal point amplitude of reference numeral 2401. As a result, in the receiving device, the estimation accuracy of the channel distortion due to the pilot symbol and the estimation accuracy of the frequency offset are improved. In addition, the noise immunity of the control symbol becomes stronger. However, the signal points are arranged so that they can be used in the method of using the transmission power amplifier described in the first embodiment.

FIG. 25 shows the signal point arrangement of 16QAM symbols and pilot symbols on the IQ plane, and reference numeral 2501 is the data symbol 23 of FIG.
02 signal point, reference numeral 2502 is preamble 230
1, the signal point of the control symbol 2304, and 2503 the signal point of the pilot symbol 2303. It is assumed that the signal point amplitudes of reference numerals 2502 and 2503, that is, the distance from the origin, is larger than the maximum signal point amplitude of reference numeral 2501. As a result, in the receiving device, the estimation accuracy of the channel distortion due to the pilot symbol and the estimation accuracy of the frequency offset are improved. In addition, the noise immunity of the control symbol becomes stronger. However, the signal points are arranged so that they can be used in the method of using the transmission power amplifier described in the first embodiment.

FIG. 26 shows a signal point arrangement of 64QAM symbols on the IQ plane according to the present embodiment, and reference numeral 2601 indicates the data symbol 230 of FIG.
Two signal points are shown, and the preamble 2301, pilot symbol 2303, and control symbol 2304 take any signal point having the maximum amplitude indicated by reference numeral 2602 in FIG.

FIG. 27 shows the configuration of the transmitting apparatus according to this embodiment. 27, portions common to FIG. 2 are assigned the same reference numerals as those in FIG. 2 and detailed description thereof is omitted. The radio unit 2701 outputs the transmission quadrature baseband signal in-phase component output from the in-phase component switching unit 204 and the quadrature component switching unit 205 based on the information of the selected modulation method included in the input control signal. It controls the gain of the reception quadrature baseband signal quadrature component and outputs the transmission signal to the transmission power amplification section 207.

FIG. 28 shows the internal structure of the signal generating section. The signal generating sections 201 and 16QAM for QPSK shown in FIG.
Signal generation unit 202, 64QAM signal generation unit 203,
27 shows detailed configurations of the QPSK signal generation unit 201, the 16QAM signal generation unit 202, and the 64QAM signal generation unit 203 in FIG. 27.

In FIG. 28, frame timing control section 2801 outputs a frame timing signal for controlling the frame timing to modulated signal generation section 2802, control signal generation section 2803, preamble signal generation section 2804, pilot signal generation section 2805, and signal selection. It outputs to each of the units 2806.

The modulated signal generator 2802 receives the input transmission digital signal and the frame timing controller 280.
Among the frame timing signals output from No. 1, a modulated signal is generated based on the frame configuration of the frame timing signal, and the transmission orthogonal baseband signal of the data symbol is output to the signal selection unit 2806.

The control signal generator 2803 receives the input control digital signal and the frame timing controller 28.
Of the frame timing signals output from 01, a control signal is generated based on the frame structure of the frame timing signal, and the transmission quadrature baseband signal of the control signal is output to the signal selection unit 2806.

Preamble signal generation section 2804 generates a preamble based on the frame structure of the frame timing signal output from frame timing control section 2801 and outputs the transmission quadrature baseband signal of the preamble to signal selection section 2806.

Pilot signal generation section 2805 generates a pilot signal based on the frame structure of the frame timing signal output from frame timing control section 2801, and outputs the transmission quadrature baseband signal of the pilot signal to signal selection section 2806. .

The signal selection unit 2806 is the modulation signal generation unit 2
Transmission orthogonal baseband signal of data symbol output from 802, transmission orthogonal baseband signal of control signal output from control signal generation unit 2803, transmission orthogonal baseband signal of preamble output from preamble signal generation unit 2804, pilot From the transmission quadrature baseband signal of the pilot signal output from the signal generation unit 2805 and the frame timing signal output from the frame timing control unit 2801, the transmission quadrature baseband signal to be output is selected based on the frame configuration of the frame timing signal. , Outputs the selected direct-transmission baseband signal.

Next, fading distortion estimation section 304 shown in FIG. 3 outputs a fading distortion estimation signal according to the modulation method from the ratio between the signal point amplitude of the pilot symbol and the maximum signal point amplitude of each modulation method. This detailed structure will be described with reference to FIG. FIG. 29 shows the configuration of the receiving apparatus according to the present embodiment. In FIG. 29,
The same parts as those in FIG. 3 are designated by the same reference numerals as those in FIG. 3 and their detailed description is omitted.

The correcting section 2901 has the fading distortion estimation signal output from the fading distortion estimating section 304,
Of the input control signals, a correction value based on the modulation method information of the control signal is calculated, the fading distortion estimation signal is multiplied by the correction value, and the corrected fading distortion estimation signal is QPSK detection section 306, 16QAM detection section. 307, 64
Output to the QAM detection unit 308. At this time, the correction value is
It is a value determined from the ratio between the signal point amplitude of the pilot symbol and the maximum signal point amplitude of each modulation method. This allows
The estimation accuracy of the fading distortion estimation signal is improved, and the reception sensitivity characteristic in the reception device is improved.

As described above, according to the present embodiment, the common power amplification section can amplify the modulation signals of a plurality of modulation systems, and the receiving device side can perform highly sensitive reception.

(Embodiment 6) FIG. 30 shows an example of a frame structure of a signal transmitted by a base station according to Embodiment 6 of the present invention. In FIG. 30, reference numeral 3001 is a data symbol with respect to the time and frequency axes, and the modulation method is, for example, QPSK, 16QAM, 64QA.
It is possible to select either M. Reference number 3
Reference numeral 002 denotes a pilot symbol, and it is assumed that the signal point amplitude of the pilot symbol on the IQ plane is variable depending on the modulation method of data symbol 3001, as described in the first embodiment.

FIG. 31 shows the configuration of the transmitting apparatus of the base station according to this embodiment. In FIG. 31, the modulator 3
101 applies modulation of the selected modulation method to the input transmission digital signal based on the information of the modulation method and frame configuration in the input control signal, and outputs the serial signal to the serial / parallel conversion unit 3102.

The serial / parallel conversion section 3102 parallel-converts the serial signal output from the modulation section 3101 and outputs the parallel signal to the discrete inverse Fourier transform section 3103. The discrete inverse Fourier transform unit 3103 converts the parallel signal output from the serial / parallel converter 3102 into
Discrete inverse Fourier transform is performed, and the signal after the discrete inverse Fourier transform is output to radio section 3104.

Radio section 3104 performs predetermined radio processing on the signal output from discrete inverse Fourier transform section 3103, and outputs a transmission signal to transmission power amplification section 3105. The transmission power amplification unit 3105 amplifies the transmission signal output from the wireless unit 3104, and transmits the amplified transmission signal to the communication terminal via the antenna 3106.

FIG. 32 shows the configuration of the receiving apparatus of the communication terminal according to this embodiment. In FIG. 32, radio section 3202 performs predetermined radio processing on a signal (received signal) received via antenna 3201 and outputs the signal to Fourier transform section 3203. The Fourier transform unit 3203
The signal output from the wireless unit 3202 is subjected to Fourier transform to convert a parallel signal into a parallel-to-serial conversion unit 3204.
Output to.

The parallel-serial conversion unit 3204 performs parallel-serial conversion on the parallel signal output from the Fourier transform unit 3203 and outputs a serial signal. The interference wave intensity estimation unit 3205 includes a parallel-serial conversion unit 320.
The interference wave intensity is estimated based on the serial signal output from the signal No. 4 (for example, from the pilot symbol), and the interference wave intensity estimation signal is output to the radio wave propagation environment estimation unit 3209.

The electric field strength estimation unit 3206 estimates the electric field strength based on the serial signal output from the parallel / serial conversion unit 3204 (for example, from pilot symbols), and outputs the electric field strength estimation signal to the radio wave propagation environment estimation unit 3209.
Output to. The multipath estimation unit 3207 estimates the number of incoming waves based on the serial signal output from the parallel / serial conversion unit 3204 (for example, from pilot symbols), and outputs the multipath estimation signal to the radio wave propagation environment estimation unit 32.
It outputs to 09.

[0195] Doppler frequency estimating section 3208 estimates the Doppler frequency based on the serial signal output from parallel-serial converting section 3204 (for example, from pilot symbols) and outputs the Doppler frequency estimating signal to radio wave propagation environment estimating section 3209. To do.

The radio wave propagation environment estimating unit 3209 has an interference wave strength estimation signal, an electric field strength estimation signal, a multipath estimation signal,
Based on the Doppler frequency estimation signal, a request for the modulation method of the transmission signal transmitted by the base station is determined and output as a radio wave propagation environment estimation signal. Alternatively, the interference wave strength estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself are output as the radio wave propagation environment estimation signal. Then, the information of the radio wave propagation environment estimation signal is transmitted from the transmission device of the communication terminal to the base station, and the modulation method of the transmission signal transmitted by the base station is changed. However, if the interference wave strength estimation signal, the electric field strength estimation signal, the multipath estimation signal, and the Doppler frequency estimation signal itself are output as the radio wave propagation environment estimation signal, the base station will determine the modulation method. .

Distortion estimating section 3210 estimates the distortion caused by the transmission path based on the serial signal output from parallel / serial converting section 3204 (for example, from pilot symbols), and outputs the distortion estimation signal to correcting section 3211. . The correction unit 3211 uses the distortion estimation signal output from the distortion estimation unit 3210 as the data symbol 30 of FIG.
A value that makes the amplitude of pilot symbol 3002 on the IQ plane variable by the modulation method of 01 is multiplied as a correction value, and the corrected distortion estimation signal is output to demodulation section 3212. The demodulation unit 3212 demodulates the serial signal output from the parallel-serial conversion unit 3204 based on the corrected distortion estimation signal output from the correction unit 3211, and outputs a received digital signal.

FIG. 33 shows a modulator 3101 shown in FIG.
Shows the internal configuration of the. In FIG. 33, QPSK serial signal generation section 3301 generates a serial signal according to the frame configuration of FIG. 30 when the modulation method information included in the control signal of the input transmission digital signal and control signal is QPSK. Then, the QPSK serial signal is output to the serial signal selection unit 3304.

16QAM serial signal generator 3302
When the information of the modulation method included in the control signal among the input transmission digital signal and control signal is 16QAM, a serial signal is generated according to the frame configuration of FIG. 30, and the 16QAM serial signal is converted into the serial signal selection unit 3304. Is output to.

64QAM serial signal generator 3303
When the information of the modulation method included in the control signal among the input transmission digital signal and control signal is 64QAM, a serial signal is generated according to the frame configuration of FIG. 30, and the 64QAM serial signal is converted into the serial signal selection unit 3304. Is output to.

The serial signal selection unit 3304 uses the QPSK
A serial signal, a 16QAM serial signal, a 64QAM serial signal, and a control signal are input, a serial signal of a specified modulation method is selected based on the modulation method information included in the control signal, and the selected serial signal is output. . The serial signal selected at this time corresponds to the serial signal output from the modulator 3101 in FIG.

However, the QPSK serial signal generator 3
301, 16QAM serial signal generators 3302, 6
The 4QAM serial signal generation unit 3303 keeps the average power of each transmission signal constant as in the first embodiment, and in the transmission power amplification unit 3105,
So that the operating range does not change even if you change the modulation method,
It is assumed that the signal point amplitudes of pilot symbols on the in-phase-quadrature plane are arranged. In addition, the transmission power amplification unit 310
In 5, the signal point amplitude of the pilot symbol on the IQ plane may be arranged so as to maximize the reception sensitivity of the communication partner within a range where distortion does not occur.

FIG. 34 shows the configuration of the transmitting apparatus of the base station according to this embodiment. 34 is different from FIG. 31 in that a control signal is input to the wireless unit 3401. The radio unit 3401 has a function of adjusting the average transmission power of the transmission signal to be equal in any modulation system, based on the information of the modulation system included in the input control signal.

As described above, the forms described in the first embodiment, the second embodiment, and the fifth embodiment can be implemented in the OFDM system.

[0205]

As described above, according to the present invention, in the wireless communication system for performing adaptive modulation, the average transmission power of the transmitting device is kept at a certain level to maximize the receiving sensitivity characteristic of the receiving device. By adopting a method in which the signal points of the pilot symbols are arranged on the IQ plane, it is possible to improve the reception sensitivity characteristic in the receiving device.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a frame structure according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a transmitting apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 1 of the present invention.

FIG. 4 is an input / output relationship diagram of a conventional transmission power amplification unit.

FIG. 5 is a constellation diagram of QPSK symbols and pilot symbol signal points on the IQ plane according to the first embodiment of the present invention.

FIG. 6 is a 16QAM symbol and pilot symbol signal point constellation diagram on the IQ plane according to the first embodiment of the present invention.

FIG. 7 is an input / output relationship diagram of two types of transmission power amplification units according to the first embodiment of the present invention.

FIG. 8 is an input / output relational diagram of the transmission power amplification unit according to the first embodiment of the present invention.

[Fig. 9] Fig. 9 is a diagram showing a power ratio of a pilot symbol and a signal point of QPSK modulation according to the first embodiment of the present invention, and a bit error rate of 1.
Graph of desired carrier power to noise power ratio required for 0 ^-4 , 10 ^-6

FIG. 10 is a block diagram showing the configuration of a transmission device that performs common amplification according to the first embodiment of the present invention.

FIG. 11 is a diagram showing an example of a frame configuration of a signal transmitted by the communication terminal according to the second embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a receiving apparatus in a base station according to Embodiment 2 of the present invention.

FIG. 13 is a diagram showing an example of a frame configuration of a signal transmitted by the base station according to the second embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a transmission device of a communication terminal according to a second embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a receiving device of a communication terminal according to a second embodiment of the present invention.

FIG. 16 is a diagram showing an example of a frame configuration of a signal transmitted by a base station in the CDMA system according to the third embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration of a base station transmitting apparatus in a CDMA system according to Embodiment 3 of the present invention.

FIG. 18 is a block diagram showing a configuration of a base station receiving device in a CDMA system according to a third embodiment of the present invention.

FIG. 19 is a diagram showing an example of a frame configuration of a signal transmitted by a communication terminal in the CDMA system according to the third embodiment of the present invention.

FIG. 20 is a block diagram showing a configuration of a transmitting apparatus of a communication terminal in a CDMA system according to Embodiment 3 of the present invention.

FIG. 21 is a block diagram showing a configuration of a receiving device of a communication terminal in a CDMA system according to a third embodiment of the present invention.

FIG. 22 is a block diagram showing a configuration of a base station receiving apparatus according to Embodiment 4 of the present invention.

FIG. 23 is a diagram showing an example of a frame configuration according to the fifth embodiment of the present invention.

FIG. 24 is a QPSK symbol and pilot symbol signal point arrangement diagram on the IQ plane according to the fifth embodiment of the present invention.

FIG. 25 is a constellation diagram of 16QAM symbols and pilot symbol signal points on the IQ plane according to the fifth embodiment of the present invention.

FIG. 26 is a 64QAM symbol signal point arrangement diagram on the IQ plane according to the fifth embodiment of the present invention.

FIG. 27 is a block diagram showing the configuration of a transmitting apparatus according to Embodiment 5 of the present invention.

FIG. 28 is a block diagram showing the configuration of an orthogonal baseband signal generation section according to Embodiment 5 of the present invention.

FIG. 29 is a block diagram showing the configuration of a receiving apparatus according to Embodiment 5 of the present invention.

FIG. 30 is a diagram showing an example of a frame configuration of a signal transmitted by the base station according to Embodiment 6 of the present invention.

FIG. 31 is a block diagram showing a configuration of a transmission apparatus of a base station according to Embodiment 6 of the present invention.

FIG. 32 is a block diagram showing a configuration of a receiving device of a communication terminal according to a sixth embodiment of the present invention.

FIG. 33 is a block diagram showing an internal configuration of a modulation section according to Embodiment 6 of the present invention.

FIG. 34 is a block diagram showing a configuration of a transmitting apparatus of a base station according to Embodiment 6 of the present invention.

FIG. 35 is a constellation diagram of 16QAM symbols and pilot symbol signal points on the IQ plane.

[Explanation of symbols]

201 QPSK signal generation unit 202 16QAM signal generation unit 203 64QAM signal generation unit 204 In-phase component switching unit 205 Quadrature component switching unit 207, 1005, 1404, 1705, 2004, 3
105 transmission power amplification section 306, 1503 QPSK detection section 307, 1504 16QAM detection section 308, 1505 64QAM detection section 303, 1506 synchronization / modulation method determination section 304 fading distortion estimation section 305 frequency offset estimation section 1001 f1 modulation section 1002 f2 modulation section 1003 fn modulator 1004, 1703 adder 1203, 2203 synchronizer 1204, 2103, 2204 detector 1205 data detector 1206, 1401, 2001 transmission data generator 1402 orthogonal baseband signal generator, 1507, 2104, 2205, 3205 interference Wave intensity estimating units 1508, 2105, 2206, 3206 Electric field intensity estimating units 1509, 2106, 2207, 3207 Multipath estimating units 1510, 2107, 2208, 3208 Doppler frequency Estimating units 1511 and 3209 Radio wave propagation environment estimating unit 1618 Modulation method determining unit 1701 Channel A spread spectrum modulating unit 1702 Channel Z spread spectrum modulating unit 1803 Channel A detecting unit 1804 Channel Z detecting unit 1805 Channel A data detecting unit 1806 Channel Z Data detection unit 1807 Channel A modulation method determination unit 1808 Channel Z modulation method determination unit 1809 Control channel transmission signal generation unit 2002 Spread spectrum modulation unit 2801 Frame timing control unit 2802 Modulation signal generation unit 2803 Control signal generation unit 2804 Preamble signal generation unit 2805 Pilot signal generation unit 2806 Signal selection units 2901 and 3211 Correction unit 3101 Modulation unit 3102 Serial parallel conversion unit 3103 Discrete inverse Fourier transform unit 3203 Fourier transform unit 3 204 parallel-serial conversion unit 3210 distortion estimation unit 3212 demodulation unit 3301 QPSK serial signal generation unit 3302 16QAM serial signal generation unit 3303 64QAM serial signal generation unit 3304 serial signal selection unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04L 27/00 H04L 27/00 Z 27/18 H04J 13/00 G (72) Inventor Masayuki Orihashi Higashimita, Tama-ku, Kawasaki City, Kanagawa Prefecture 3-10-1 Matsushita Giken Co., Ltd. (72) Inventor Akihiko Matsuoka 3-10-1 Higashisanda Tama-ku, Kawasaki City, Kanagawa Matsushita Giken Co., Ltd. (56) Reference JP-A-9-200282 (JP , A) JP 57-155856 (JP, A) JP 57-159148 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 27/34 H04B 1/04 H04B 7/26 102 H04J 11/00 H04J 13/04 H04L 27/00 H04L 27/18

Claims (7)

(57) [Claims] 1. A plurality of signal generating means for generating quadrature baseband signals by mutually different modulation systems, a switching means for selecting only a target signal from the signals output from the plurality of signal generating means, and the switching. A wireless means for performing a predetermined wireless processing on the quadrature baseband signal selected by the means; and a power amplifying means for amplifying the power of the transmission signal output from the wireless means. A wireless communication device for adjusting the transmission power of symbols for demodulation so that the average transmission output powers of transmission signals are equal to each other and the operating range of the power amplification means becomes a predetermined value. 2. The wireless communication device according to claim 1, wherein the predetermined value is the same value for each modulation scheme. 3. A plurality of signal generating means for generating quadrature baseband signals by mutually different modulation systems, a switching means for selecting only a target signal among the signals output from the plurality of signal generating means, and the switching A wireless means for performing a predetermined wireless processing on the quadrature baseband signal selected by the means; and a power amplifying means for amplifying the power of the transmission signal output from the wireless means. A wireless communication apparatus that adjusts the transmission power of symbols for demodulation so that the average transmission output powers of transmission signals are equal to each other and the reception sensitivity has an optimum value. 4. A plurality of signal generation means for generating a serial signal by a modulation method different from each other for a transmission digital signal, and a switching means for selecting only a target signal among the serial signals output from the plurality of signal generation means. A serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal; a discrete inverse Fourier transform means for performing a discrete inverse Fourier transform of the serial-parallel-converted parallel signal; Wireless means for performing a predetermined wireless process, and power amplification means for amplifying the power of the transmission signal output from the wireless means, wherein the average transmission output power of the transmission signal by each modulation method is equal to each other, Set the transmission power of symbols for demodulation so that the operating range of the power amplification means becomes a predetermined value. A wireless communications apparatus that integer. 5. The wireless communication device according to claim 4, wherein the predetermined value is the same value for each modulation scheme. 6. A plurality of signal generating means for generating a serial signal of a transmission digital signal by different modulation methods, and a switching means for selecting only a target signal among the serial signals output from the plurality of signal generating means. , A serial-parallel conversion means for converting the serial signal output from the switching means into a parallel signal, a discrete inverse Fourier transform means for performing a discrete inverse Fourier transform of the serial-parallel converted parallel signal, and a discrete inverse Fourier-transformed signal Radio means for performing a predetermined radio processing, and power amplification means for amplifying the power of the transmission signal output from the radio means, wherein the average transmission output power of the transmission signals by each modulation method is equal to each other A wireless communication device that adjusts the transmission power of symbols for demodulation so that the sensitivity has an optimum value. 7. A correction value is determined from a ratio of a signal point amplitude of a symbol for demodulation received from the wireless communication device according to any one of claims 1 to 6 and a maximum signal point amplitude of each modulation method. Then, the wireless communication apparatus that performs detection by multiplying the transmission path distortion estimation signal in which the distortion due to the transmission path is estimated by the correction value.