JP4283714B2 - Transmission signal power control method and apparatus - Google Patents

Description

  The present invention relates to a carrier-free wireless communication system that transmits and receives baseband signals wirelessly without using carrier signals, and more particularly to a transmission signal power control method and apparatus for controlling the power of transmission signals.

  FIG. 10 shows an example of a conventional transmission signal power control apparatus in wireless communication (for example, see Non-Patent Document 1). The example of FIG. 10 includes an input stage transistor M1, an output stage transistor M2, an input stage matching circuit MAT1, a matching circuit MAT2 between the input stage and the output stage, and an output stage matching circuit MAT3. The configuration of the transmission signal power control device is incorporated in a power amplifier including a capacitor C1 that connects the circuit MAT2 and the transistor M2, a capacitor C2 that connects the matching circuit MAT3 and the load impedance RL, and the choke coils RFC1 and RFC2. Is. In FIG. 10, RL is the impedance of the transmitting antenna.

  A transmission signal transmitted by wireless communication is an analog signal obtained by modulating a sine wave carrier signal. The transmission signal Vin is input to the power amplifier at the time of transmission, is amplified, and is transmitted from the transmission antenna. In order to control the power of the transmission signal, the gain of the power amplifier may be controlled. There are several means for controlling the gain of the power amplifier. In the case of FIG. 10, the gain can be adjusted by controlling the bias voltage Vb of the transistor M2 in the output stage.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
Translated by Tadahiro Kuroda, “RF Microelectronics”, Maruzen Co., Ltd., p. 351-352, ISBN 4-621-07005-3

In the conventional transmission power control apparatus, the gain of the power amplifier is controlled in order to control the transmission signal power. As shown in FIG. 10, since a power amplifier is generally composed of a high-frequency analog circuit, there is a problem that design is difficult and costly.
By the way, in a carrier-free wireless communication system that wirelessly transmits and receives baseband signals without using carrier signals, wireless communication is performed using a very wide frequency band, so that a power amplifier must also have a very wide bandwidth. Become. Wideband power amplifiers are more complicated to design, difficult to implement, and costly, and it is further necessary to adjust the gain of the power amplifier to control the transmit signal power while maintaining the wide bandwidth of the power amplifier. There was a problem that it was difficult and costly.

  The present invention solves such a conventional problem, and is a simple, low-cost, low-power transmission signal power in a carrier-free wireless communication system that transmits and receives a baseband signal wirelessly without using a carrier signal. It is an object to provide a control method and apparatus.

The present invention is a transmission signal power control method in a wireless communication system that wirelessly transmits and receives a baseband signal without using a carrier wave signal, and includes a group of one or more pulses synchronized with the rising edge of the baseband signal to be transmitted. the first square wave signal and said to generate a second square wave signal formed from a group of one or more pulses in synchronization with the falling edge of the baseband signal is supplied to the transmission antenna having a predetermined center frequency comprising, The power of the transmission signal transmitted from the transmission antenna is controlled by the number of pulses included in each pulse group of the first and second square wave signals.
Also, in one configuration example of the transmission signal power control method of the present invention, when the pulse width of the square wave signal is T, the center frequency of the antenna used for transmission / reception is 1 / 2T + n / T (n is an integer of 0 or more) ).

Further, the transmission signal power control apparatus of the present invention includes a first square wave signal composed of a group of one or more pulses synchronized with the rising edge of the baseband signal to be transmitted and 1 synchronized with the falling edge of the baseband signal. A square wave signal generating means for generating a second square wave signal composed of a group of more than two pulses and supplying the second square wave signal to a transmission antenna having a predetermined center frequency; and power of the transmission signal transmitted from the transmission antenna Control means for controlling the number of pulses included in each pulse group of the first and second square wave signals.
Further, in one configuration example of the transmission signal power control apparatus of the present invention, when the pulse width of the square wave signal is T, the center frequency of the antenna used for transmission / reception is 1 / 2T + n / T (n is an integer of 0 or more) ).

Further, in one configuration example of the transmission signal power control apparatus according to the present invention, the square wave signal generation means includes the first and second square wave signals having the same number of pulses as one group, and the number of pulses is mutually equal. a generating circuit for generating a plurality of different groups, is composed of a switch for selectively outputting one of the plurality of groups, the control means, the switch control circuits or we configured to control the pre-Symbol switch It is what is done.
In the configuration example of the transmission signal power control apparatus according to the present invention, the generation circuit includes a plurality of shift registers and an exclusive OR circuit.
Further, in one configuration example of the transmission signal power control method of the present invention, the bit rate of the baseband signal is set to 1 / N (N is an integer of 2 or more), and the number of pulses of the square wave signal is increased N times. It is what I did.

  According to the present invention, the transmission signal power is controlled by generating a square wave signal synchronized with the rise and fall of the baseband signal to be transmitted, supplying the square wave signal to the transmission antenna, and controlling the pulse width of the square wave signal. can do. The transmission signal power control device can be realized with a simple digital circuit, and it is not necessary to use a power amplifier of an analog circuit like a transmitter of a conventional wireless communication system, so the design is simplified, and transmission is performed at low cost and low power. It becomes possible to control the signal power.

  Moreover, according to the present invention, the transmission signal power can be controlled by controlling the pulse width and the number of pulses of the square wave signal. The transmission signal power control device can be realized with a simple digital circuit, and it is not necessary to use a power amplifier of an analog circuit like a transmitter of a conventional wireless communication system, so the design is simplified, and transmission is performed at low cost and low power. It becomes possible to control the signal power.

  Further, the transmission signal power control can be effectively performed by setting the center frequency of the antenna used for transmission / reception to 1 / 2T + n / T (n is an integer of 0 or more) with respect to the pulse width T of the square wave signal. Can do.

  In addition, the baseband signal bit rate is set to 1 / N (N is an integer of 2 or more), and the number of square wave signal pulses is increased N times so that the specified value of the transmission signal power specified by the Radio Law etc. You can extend the communication distance while keeping

Hereinafter, a transmission power control apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[First Embodiment]
A transmission power control apparatus according to the present embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a wireless communication system to which the transmission power control apparatus of this embodiment is applied. This wireless communication system includes a transmitter 1 and a receiver 2.

On the transmitter 1 side, a baseband signal to be transmitted is directly supplied to the transmitting antenna 10. Thereby, the signal of the frequency component in the zone | band of the transmission antenna 10 is transmitted as a transmission signal among all the bands of a baseband signal.
On the receiver 2 side, the signal received by the receiving antenna 20 is amplified by a low noise amplifier (hereinafter referred to as LNA) 21 and then envelope detected by an envelope detector 22, and the signal detected by the envelope is counted by a counter 23. Thus, the baseband signal is reproduced.

Typical points at point A (input of transmission antenna 10), point B (output of transmission antenna 10), point C (output of envelope detector 22), point D (output of counter 23) of the wireless communication system of FIG. A simple signal waveform is shown in FIG. In FIG. 2, the vertical axis represents signal intensity, and the horizontal axis represents time.
The signal at point A is a baseband signal to be transmitted. The signal at point B is a transmission signal output from the transmission antenna 10 when a baseband signal is supplied to the transmission antenna 10. Since only the high-frequency component of the baseband signal is output from the transmission antenna 10, a pulse signal synchronized with the rise and fall of the baseband signal is transmitted as a transmission signal as shown in FIG.

  The signal at point C is an envelope detection signal when the reception signal received by the receiving antenna 20 (the same signal as point B) is amplified by the LNA 21 and envelope detection is performed. As shown in FIG. 2C, it can be seen that the peak of the received signal is detected by envelope detection. The signal at point D is a baseband signal that is output when the envelope detection signal is counted by the 1-bit counter 23. As shown in FIG. 2D, every time a peak of the envelope detection signal is detected, 1 and 0 are inverted, and it can be seen that the baseband signal at point A is correctly reproduced.

  In the method of the wireless communication system of FIG. 1, since 1 and 0 are all inverted when a 1-bit error occurs, information is not put on the absolute phase of the baseband signal, but a difference is generated in the baseband signal to be transmitted. If modulation is performed in advance and information is put on the deviation of 1 and 0, there is no problem even if the baseband signal reproduced on the receiver 2 side is inverted.

In the wireless communication system of FIG. 1, it is necessary to provide a power amplifier that matches the band of the transmission antenna 10 in order to control the transmission signal power. However, the wideband power amplifier has a complicated design and costs. There is.
Therefore, in the present embodiment, a square wave signal synchronized with the rise and fall of the baseband signal to be transmitted is generated and supplied to the transmission antenna 10, and the transmission signal power is controlled by controlling the pulse width of this square wave signal. It was decided to control.

  FIG. 3 is a block diagram showing the configuration of the wireless communication system according to the first embodiment of the present invention. The same components as those in FIG. The transmitter 1a of the present embodiment is obtained by adding a transmission signal power control device 11 in front of the transmission antenna 10 to the transmitter 1 of FIG. The transmission signal power control device 11 generates a square wave signal synchronized with the rising and falling edges of the baseband signal to be transmitted and supplies the square wave signal to the transmission antenna 10 and power of the transmission signal. And a control means (not shown) for controlling the frequency with the pulse width of the square wave signal.

  Typical signal waveforms at point E (output of the transmission signal power control device 11), point F (output of the transmission antenna 10), and point G (output of the envelope detector 22) of the wireless communication system of FIG. Shown in The vertical axis in FIG. 4 is signal intensity, and the horizontal axis is time. For comparison with the wireless communication system of FIG. 1, signals at points A, B, and C when the transmission signal power control device 11 is not added are also shown. That is, FIG. 4A to FIG. 4C show the same signals as FIG. 2A to FIG.

  The signal at point E is a square wave signal synchronized with the rising and falling edges of the baseband signal shown in FIG. The signal at point F is a transmission signal output from the transmission antenna 10 when a square wave signal is supplied to the transmission antenna 10. The signal at point G is an envelope detection signal when the reception signal received by the reception antenna 20 (the same signal as point F) is amplified by the LNA 21 and envelope detection is performed. The peak value of the envelope detection signal in FIG. 4 (f) is the same as the envelope detection signal shown in FIG. 4 (c), and is a square wave signal synchronized with the rising and falling edges of the baseband signal to be transmitted. It can be seen that communication is possible in the same manner as in FIG.

Hereinafter, the reason why the transmission signal power can be controlled by controlling the pulse width of the square wave signal will be described with reference to FIG. 5A to 5C, the vertical axis represents spectrum intensity, the horizontal axis represents frequency, the vertical axis in FIGS. 5D to 5F represents signal intensity, and the horizontal axis represents time.
FIG. 5A shows the frequency spectrum of the baseband signal to be transmitted, and FIG. 5D shows the signal waveform of this baseband signal.

  In the present embodiment, the transmission signal power control device 11 generates a square wave signal synchronized with the rising and falling edges of the baseband signal to be transmitted. If the pulse width of the square wave signal is T, the frequency spectrum of the square wave signal is as shown in FIG. 5B, and the signal waveform is as shown in FIG. If the pulse width of the square wave signal is further reduced to T ′, the frequency spectrum is as shown in FIG. 5C, and the signal waveform is as shown in FIG.

  When the pulse width of the square wave signal is shortened, the zero point of the fundamental component of the frequency spectrum moves to the high frequency side from 1 / T to 1 / T ′. Assuming that the bands of the antennas 10 and 20 used for transmission and reception are BA, the zero point of the fundamental wave component of the frequency spectrum moves from 1 / T to 1 / T ′ to the high frequency side, so that the signal power within the antenna band BA As shown in FIG. 5B, the hatched portion increases from the shaded portion shown in FIG. 5B to the shaded portion shown in FIG. Conversely, when the pulse width of the square wave signal is increased, the zero point of the fundamental wave component of the frequency spectrum moves from 1 / T ′ to 1 / T to the low frequency side, and the signal power in the antenna band BA is as shown in FIG. The hatched portion shown in (c) is reduced to the hatched portion shown in FIG. 5 (b).

  In the description of FIG. 5, the case where the antenna band BA is included in the fundamental wave component of the square wave signal has been described, but the same applies to the case where the antenna band BA is present in the first harmonic, the second harmonic, and the like of the square wave signal. By controlling the pulse width of the square wave signal, the signal power transmitted from the transmitting antenna 10 can be controlled.

As described above, in the present embodiment, a square wave signal synchronized with the rise and fall of the baseband signal to be transmitted is generated and supplied to the transmission antenna 10, and the pulse width of this square wave signal is controlled. Thus, the transmission signal power can be controlled. The radio communication system according to the present embodiment is intended for weak radio communication at a short distance, and the transmission signal power control device 11 can be realized by a simple digital circuit. The radio communication system of the conventional radio communication system shown in FIG. Since it is not necessary to use a power amplifier of an analog circuit unlike a transmitter, the design is simplified, and transmission signal power can be controlled at low cost and low power.
In the present embodiment, the baseband signal is demodulated by the 1-bit counter 23, but the present invention is not limited to this, as long as it performs the same function as the 1-bit counter.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 6A is a block diagram showing a configuration of a wireless communication system according to the second embodiment of the present invention. The same components as those in FIG. 3 are denoted by the same reference numerals. The radio communication system of the present embodiment shows a specific example of the radio communication system of FIG.
The transmission signal power control device 11 of the transmitter 1a includes a shift register 110, an exclusive OR circuit (hereinafter referred to as XOR) 111, and a clock control circuit 112. The shift register 110 and XOR constitute square wave signal generation means, and the clock control circuit 112 constitutes control means.

  The shift register 110 delays the baseband signal to be transmitted by the period of the clock signal CLK. The XOR 111 performs an exclusive OR operation on the baseband signal to be transmitted and the signal output from the shift register 110. Thereby, a square wave signal synchronized with the rise and fall of the baseband signal to be transmitted from the XOR 111 is output. At this time, since the pulse width of the square wave signal is determined by the cycle of the clock signal CLK output from the clock control circuit 112, the clock control circuit 112 can control the transmission signal power by changing the cycle of the clock signal CLK. it can.

The envelope detector 22 of the receiver 2 includes a multiplier 220 and a comparator 221. The multiplier 220 multiplies the reception signals amplified by the LNA 21, and the comparator 221 outputs a signal of a predetermined level or higher among the outputs of the multiplier 220.
Signal waveforms at points E, F, and G in FIG. 6A are the same as the signal waveforms of the first embodiment shown in FIGS. 4D, 4E, and 4F. is there.
Thus, also in this embodiment, the same effect as that of the first embodiment can be obtained.

  As shown in FIG. 6B, the envelope detector 22 of the receiver 2 may be composed of a diode 222, resistors 223 and 224, a capacitor 225, a low-pass filter 226, and a comparator 227. In FIG. 6B, bias is a bias voltage applied to the diode 222. The envelope detector 22 performs diode detection on the received signal amplified by the LNA 21.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. FIG. 7 is a block diagram showing the configuration of the transmitter of the wireless communication system according to the third embodiment of the present invention. The same components as those in FIGS. 3 and 6 are given the same reference numerals. Since the receiver has the same configuration as that of the second embodiment, the description is omitted in FIG.

In this embodiment, a square wave signal is used as in the first and second embodiments, but the transmission signal power is controlled by the pulse width of the square wave signal and the number of pulses.
The transmitter 1b according to the present embodiment includes a transmission signal power control device 11b and a transmission antenna 10. The transmission signal power control device 11b includes a square wave signal generation unit and a control unit, and the square wave signal generation unit includes a generation circuit that generates a plurality of square wave signals having different numbers of pulses and a switch 119. . The generation circuit is a combination of a plurality of shift registers and XOR. In the example of FIG. 7, the generation circuit includes shift registers 110, 113, 114, 116, 117 and XORs 111, 115, 118. Further, the clock control circuit 112 and the switch control circuit 120 constitute a control means.

Hereinafter, the transmission signal power control method according to the present embodiment will be described with reference to FIG. 8 (a) to 8 (c), the vertical axis represents the spectral intensity (unit: dB), the horizontal axis represents the frequency, and the vertical axis in FIGS. 8 (d) to 8 (f) represents the signal intensity, and the horizontal axis. Is time.
When the switch 119 is controlled by the switch control circuit 120 in the transmitter 1b of FIG. 7 and the output of the XOR 111 is selected, the frequency spectrum of the square wave signal output from the switch 119 is as shown in FIG. The signal waveform is as shown in FIG. This square wave signal has one pulse corresponding to one rising or falling edge of the baseband signal to be transmitted, and is the same as the square wave signal described in the first and second embodiments. It is.

  On the other hand, the XOR 115 outputs a square wave signal in which the number of pulses corresponding to one rising or falling edge of the baseband signal is two. The reason is that the output signal of the XOR 111 is delayed by two cycles of the clock signal CLK by the shift registers 113 and 114, and the exclusive OR operation of the output signal of the XOR 111 and the output signal of the shift register 114 is performed by the XOR 115. It is. Therefore, when the switch control circuit 120 controls the switch 119 to select the output of the XOR 115, the frequency spectrum of the square wave signal output from the switch 119 is as shown in FIG. 8B, and the signal waveform is as shown in FIG. As shown in (e).

  The XOR 118 outputs a square wave signal having three pulses corresponding to one rising or falling edge of the baseband signal. This is because the output signal of the XOR 115 is delayed by two cycles of the clock signal CLK by the shift registers 116 and 117, and the XOR 118 performs an exclusive OR operation between the output signal of the XOR 111 and the output signal of the shift register 117. It is. Therefore, when the switch control circuit 120 controls the switch 119 to select the output of the XOR 118, the frequency spectrum of the square wave signal output from the switch 119 becomes as shown in FIG. 8C, and the signal waveform thereof is as shown in FIG. As shown in (f).

  As can be seen from FIGS. 8A to 8C, when the number of pulses of the square wave signal is increased, the center frequency 1 / 2T of the harmonic component of the square wave signal (T is the pulse width), 3 / The signal spectrum concentrates on 2T, 5 / 2T,..., And the peak value of the signal spectrum increases. Further, side lobes appear on both sides of the center frequencies 1 / 2T, 3 / 2T, 5 / 2T,... By the number of pulses increased. For example, when the number of square wave signal pulses is increased by two from the state of FIG. 8D to the state of FIG. 8F, two side lobes are formed on both sides of each intermediate frequency as shown in FIG. 8C. Appears one by one.

  Therefore, in the present embodiment, by setting the center frequency of the transmission antenna 10 and the reception antenna 20 to the center frequency of the harmonic component of the square wave signal output from the transmission signal power control device 11b, the pulse of the square wave signal is set. Thus, the transmission signal power can be controlled by the number of. That is, the center frequency of the antennas 10 and 20 used for transmission / reception may be set to 1 / 2T + n / T (n is an integer of 0 or more) with respect to the pulse width T of the square wave signal. However, as n increases, that is, as the center frequency of the antennas 10 and 20 is set to the center frequency of higher-order harmonic components, the peak of the signal spectrum as shown in FIGS. 8 (a) to 8 (c). Therefore, the signal power that can be transmitted is small.

The change in the transmission signal power is caused by the change in the square wave signal supplied to the transmission antenna 10, and is shown in FIG. 8 (e) with respect to the one-pulse square wave signal shown in FIG. 8 (d). When a two-pulse square wave signal is used, the transmission signal power increases by about 6 dB in terms of energy. By using the same conversion, when the three-pulse square wave signal shown in FIG. 8F is used for the one-pulse square wave signal, the transmission signal power increases by about 9.5 dB.
Needless to say, similarly to the first and second embodiments, the transmission signal power can also be controlled by the clock control circuit 112 serving as a pulse width control circuit changing the cycle of the clock signal CLK.

  Further, when it is desired to finely control the transmission signal power, it may be as shown in FIG. 9 (a) and 9 (b), the vertical axis represents spectrum intensity (unit: dB), the horizontal axis represents frequency, and the vertical axes in FIGS. 9 (c) and 9 (d) represent signal intensity and horizontal axis. Is time. 9 (a) and 9 (c) are the same as FIGS. 8 (a) and 8 (d), respectively. Corresponding to one rising or falling edge of the baseband signal, the square wave signal in FIG. 9 (c) changes twice in total, rising and falling edges of the pulse.

  On the other hand, the square wave signal of FIG. 9D showing the frequency spectrum as shown in FIG. 9B has two rising edges and one falling edge, or one falling edge and two rising edges. It has changed three times in total. In this case, the change is 1.5 times the square wave signal shown in FIG. 9C, and the transmission signal power increases by 3.5 dB in terms of energy.

  If the number of square wave signal pulses supplied to the transmitting antenna 10 is increased too much, intersymbol interference (a phenomenon in which the peaks of the envelope detection signals shown in FIG. 2 (c) approach each other) may occur. In this case, intersymbol interference can be avoided by lowering the bit rate of the baseband signal.

As described above, if the number of pulses of the square wave signal supplied to the transmission antenna 10 is increased, the power of the transmission signal transmitted from the transmission antenna 10 increases. This power is a specified value defined by the Radio Law. Cannot be exceeded. Therefore, when it is desired to increase the communication distance, the bit rate of the baseband signal to be transmitted may be reduced to increase the number of pulses of the square wave signal. Specifically, when the bit rate is reduced to 1 / N (N is an integer of 2 or more), the number of pulses of the square wave signal can be increased up to N times. Even if the bit rate is set to 1 / N and the number of square wave signal pulses is changed to N times, the total number of pulses transmitted per unit time remains the same as before, so the average transmission power per unit time is It is constant, and it is possible to extend the communication distance while keeping the specified value.
As described above, also in this embodiment, the same effects as those in the first and second embodiments can be obtained.

  The present invention can be applied to wireless communication in which digital signals are transmitted and received by electromagnetic waves.

It is a block diagram which shows the structural example of a radio | wireless communications system. In the wireless communication system of FIG. 1, the baseband signal input to the transmission antenna, the transmission signal output from the transmission antenna, the envelope detection signal output from the envelope detector, and the signal waveform of the baseband signal output from the counter It is a figure which shows one example of. It is a block diagram which shows the structure of the radio | wireless communications system used as the 1st Embodiment of this invention. The figure which shows an example of the signal waveform of the square wave signal output from the transmission signal power control apparatus in the radio | wireless communications system of FIG. 3, the transmission signal output from a transmission antenna, and the envelope detection signal output from an envelope detector. It is. FIG. 4 is a diagram illustrating a baseband signal input to a transmission signal power control device and a frequency spectrum and a signal waveform of a square wave signal output from the transmission signal power control device in the wireless communication system of FIG. 3. It is a block diagram which shows the structure of the radio | wireless communications system and envelope detector used as the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the transmitter of the radio | wireless communications system which becomes the 3rd Embodiment of this invention. It is a figure which shows one example of the frequency spectrum and signal waveform of a square wave signal output from a transmission signal power control apparatus in the transmitter of FIG. It is a figure which shows the other example of the frequency spectrum and signal waveform of a square wave signal output from a transmission signal power control apparatus in the transmitter of FIG. It is a block diagram which shows the structure of the conventional transmission signal power control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Transmitter, 2 ... Receiver, 10 ... Transmission antenna, 11, 11b ... Transmission signal power control apparatus, 20 ... Reception antenna, 21 ... Low noise amplifier, 22 ... Envelope detector, 23 ... Counter, 110, 113, 114, 116, 117 ... shift register, 111, 115, 118 ... exclusive OR circuit, 112 ... clock control circuit, 119 ... switch, 120 ... switch control circuit, 220 ... multiplier, 221 ... comparator.

Claims (7)

A transmission signal power control method in a wireless communication system that wirelessly transmits and receives a baseband signal without using a carrier wave signal,
A first square wave signal composed of a group of one or more pulses synchronized with the rising edge of the baseband signal to be transmitted, and a second square composed of a group of one or more pulses synchronized with the falling edge of the baseband signal. A pulse signal included in each pulse group of the first and second square wave signals is generated by supplying a wave signal to a transmission antenna having a predetermined center frequency and transmitting the power of the transmission signal transmitted from the transmission antenna. The transmission signal power control method is characterized in that it is controlled by the number of The transmission signal power control method according to claim 1,
A transmission signal power control method, wherein a center frequency of an antenna used for transmission / reception is 1 / 2T + n / T (n is an integer of 0 or more), where T is a pulse width of the square wave signal . A transmission signal power control apparatus in a wireless communication system that wirelessly transmits and receives a baseband signal without using a carrier wave signal,
A first square wave signal composed of a group of one or more pulses synchronized with the rising edge of the baseband signal to be transmitted, and a second square composed of a group of one or more pulses synchronized with the falling edge of the baseband signal. A square wave signal generating means for generating a wave signal and supplying the wave signal to a transmission antenna having a predetermined center frequency, and transmitting the power of the transmission signal transmitted from the transmission antenna to each pulse of the first and second square wave signals. And a control means for controlling by the number of pulses included in the group . The transmission signal power control apparatus according to claim 3,
A transmission signal power control apparatus, wherein a center frequency of an antenna used for transmission / reception is 1 / 2T + n / T (n is an integer of 0 or more), where T is a pulse width of the square wave signal . The transmission signal power control apparatus according to claim 3,
The square wave signal generating means includes the generation circuit for generating a plurality of groups having different numbers of pulses, with the first and second square wave signals having the same number of pulses as one group, and among the plurality of groups. It consists of a switch that selects and outputs one of them,
The transmission signal power control apparatus, wherein the control means comprises a switch control circuit for controlling the switch . The transmission signal power control apparatus according to claim 5,
The transmission signal power control apparatus , wherein the generation circuit includes a plurality of shift registers and an exclusive OR circuit . The transmission signal power control method according to claim 1 or 2 ,
A transmission signal power control method, wherein a bit rate of the baseband signal is 1 / N (N is an integer of 2 or more), and the number of pulses of the square wave signal is increased N times.

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