JPH11186933A - Digital radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain an oscillation frequency to be fixed, even when voltage fluctuation due to the turning on/off of a power amplifier circuit is generated by supplying a stable voltage from a first regulator to a local oscillator part and supplying the stable voltage from a second regulator to the power amplifier circuit. SOLUTION: A stable voltage VC1 is supplied from a first regulator 11 to a local oscillation part 21, and a stable voltage VC2 is supplied from a second regulator 12 to a power amplifier circuit 222. Even if voltage fluctuations due to the turning on/off of the power amplifier circuit 222 is generated between a transmission slot and a reception slot, it is limited to the voltage fluctuations in the second regulator 12 for supplying the stable voltage VC2 to the power amplifier circuit 222, and the first regulator 11 for supplying the stable voltage VC1 to the local oscillation part 21 is affected only slightly. Thus, the oscillation frequencies fr and ft of the local oscillation part 21 are maintained fixed, transmission is performed through highly accurate modulation, and reception is performed by a low-bit error rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital radio communication device. The digital wireless communication device according to the present invention includes digital PDC, PHS, and the like.

[0002]

2. Description of the Related Art A digital radio communication apparatus of this type generally includes a high-frequency circuit section, a signal processing section, and an interface section. Has become. The high frequency circuit section
It includes a local oscillator and a transmitter / receiver, and synthesizes a frequency signal required in the transmitter / receiver from an oscillation frequency supplied from the local oscillator.

[0003] The local oscillator generates a frequency signal for synthesizing the transmission frequency and the reception intermediate frequency required in the transmission / reception unit, and therefore requires a high degree of frequency stability and accuracy.

[0004] The transmitting section includes a power amplifying circuit, and synthesizes a required transmitting frequency by using an oscillating frequency supplied from the local oscillating section. The power amplifier circuit operates by being supplied with an operating voltage from a power supply unit, and amplifies a transmission signal. In order to perform wireless communication satisfactorily, for example, an output 10
A power amplifier circuit of 0 mW is used. In this case, the current consumption of the power amplifier circuit is about 200 mA, which is significantly larger than other components such as the receiving unit.

[0005] By the way, in this type of digital radio communication apparatus, generally, time division multiplex communication (Time Division Multipl.
e Access, hereinafter referred to as TDMA),
The transmission unit is turned on / off in accordance with the transmission slot. Therefore, the power supply unit is 0 m
An on / off current that fluctuates between A and 200 mA must be supplied, causing a large voltage fluctuation in the operating voltage supplied to each circuit from the power supply unit. For example, as an example, the internal resistance of the power supply unit is 1Ω, and the output current is 0 mA and 200 mA.
If it fluctuates between mA, the output voltage of the power supply will fluctuate by about 200 mV.

Conventionally, a power amplifying circuit of a high-frequency circuit section;
Since the operating power is supplied from the same power supply unit to the local oscillation unit, when the output voltage of the power supply unit fluctuates due to the ON / OFF driving of the transmission unit, the power is supplied to the local oscillation unit. Voltage also fluctuates. The local oscillation unit is vulnerable to voltage fluctuations.
The oscillation frequency fluctuates by several tens of kHz.

The transmitting unit and the receiving unit synthesize the frequency of the transmission signal or the received intermediate signal based on the oscillation frequency supplied from the local oscillating unit. Is deteriorated, and the bit error rate increases in the receiving unit.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital radio communication device and a high-frequency unit capable of maintaining a constant oscillation frequency of a local oscillator.

Another object of the present invention is to provide a digital radio communication device and a high-frequency unit that can transmit with high-precision modulation and receive with a low bit error rate.

[0010]

To solve the above-mentioned problems, a digital radio communication apparatus according to the present invention includes a voltage stabilizing section and a high-frequency circuit section. The voltage stabilizing section includes a first
And a second regulator, and generates a stable voltage from a power supply voltage supplied from a power supply.

The high-frequency circuit section includes a local oscillation section, a transmission section, and a reception section. The local oscillator is supplied with a stable voltage from the first regulator and oscillates at a constant frequency.

The transmitting section includes a transmitting circuit and a power amplifier circuit. The transmission circuit generates a transmission signal using an oscillation frequency supplied from the local oscillator. The power amplifier circuit is supplied with a stable voltage from the second regulator and amplifies the transmission signal.

[0013] The receiving unit converts a received signal into an intermediate frequency signal using an oscillation frequency supplied from the local oscillation unit.

The digital radio communication apparatus according to the present invention has T
Driven by the DMA method. First, in the transmission slot in which the transmitting unit operates, the transmitting unit uses the oscillation frequency supplied from the local oscillating unit to use, for example, 19
The transmission signal frequency in the 00 MHz band is synthesized. This transmission signal is amplified by a power amplifier circuit, further supplied to an antenna via an antenna duplexer or the like, and radiated into the air. As described above, for example, a power amplifier circuit having an output of 100 mW is used as the power amplifier circuit.

Next, in the receiving slot in which the receiving section operates, a reception signal is guided from the antenna and the antenna duplexer to the receiving section. The reception signal frequency is 1900 MH in PHS
The z band. The receiving unit finally combines a reception signal having an intermediate frequency of, for example, 10.8 MHz by using the oscillation frequency supplied from the local oscillation unit. This 10.8MHz
Is processed in the signal processing unit, and further,
It is supplied to the interface unit. The interface unit includes a microphone, a speaker, and the like.

In the reception slot, the power amplification circuit of the transmission section does not operate. Therefore, a large current fluctuation occurs between the transmission slot and the reception slot, and the voltage fluctuates.

In the present invention, the voltage stabilizer includes a first regulator and a second regulator, supplies a stable voltage from the first regulator to the local oscillator, and supplies a stable voltage to the power amplifier circuit. Thus, a stable voltage is supplied from the second regulator. Therefore, even if a voltage fluctuation occurs between the transmission slot and the reception slot due to ON / OFF of the power amplification circuit, the voltage fluctuation is caused by the voltage fluctuation in the second regulator that supplies a stable voltage to the power amplification circuit. The effect on the first regulator that supplies a stable voltage to the local oscillator is small. That is, the voltage supplied from the first regulator to the local oscillation unit does not fluctuate greatly even when the power amplifier circuit performs an on / off operation. For this reason, the oscillation frequency of the local oscillator is kept constant. Further, it is possible to transmit with high-precision modulation and receive with low bit error rate.

In the high-frequency circuit section, a circuit configuration for supplying a stable voltage from the first regulator or a stable voltage from the second regulator may be applied to the transmitting section and the receiving section except for the power amplifier circuit. A circuit configuration may be used.

As another mode, the voltage stabilizing unit further includes a third regulator, and adopts a circuit configuration for supplying a stable voltage from the third regulator to the transmitting unit and the receiving unit excluding the power amplifier circuit. You can also.

In this case, the first regulator may employ a circuit configuration in which the stable voltage supplied from the third regulator is further stabilized and supplied to the local oscillator. The ripple rejection characteristic of a general regulator is 40 to 50 dB.
A remarkable effect of improving the ripple rejection characteristic of about 100 dB can be obtained. As a result, the local oscillation unit is completely protected from noises and various noises generated when the clock frequency of the signal processing unit is increased. Further, voltage fluctuation accompanying the TDMA method is eliminated, and the accuracy of the oscillation frequency can be maintained.
Furthermore, even when a personal computer power supply having poor noise characteristics is used, the local oscillator can be protected from noise coming from the personal computer power supply, and the accuracy of the oscillation frequency can be maintained.

The voltage stabilizer may use a power supplied from a battery or a power supplied from a computer.

Further, the circuit configuration for supplying a stable voltage from the second regulator to the signal processing unit normally included in the digital wireless communication device realizes the digital wireless communication device in which the local oscillation unit is not affected by noise. It is effective for

The present invention further provides a high-frequency unit in which a voltage stabilizing unit and a high-frequency circuit unit are unitized among circuit parts included in a digital wireless communication apparatus, and a digital wireless communication apparatus incorporating such a high-frequency unit. Provide equipment.

Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The accompanying drawings merely show examples.

[0025]

FIG. 1 is a block diagram of a digital radio communication apparatus according to the present invention. For example, in PHS, TDM using a frequency of 1900 MHz band for transmission and reception is used.
It is configured as an A system. The digital wireless communication device shown in FIG. 1 includes a voltage stabilizer 1 and a high-frequency circuit 2. In the figure, reference numeral 4 is an antenna duplexer, 5 is an antenna, 6 is a signal processing unit, and 7 is an interface unit. The antenna duplexer 4 is a PIN diode or GaAsFET-I
A switching circuit composed of C or the like may be used.

The voltage stabilizer 1 includes a first regulator 11
And a second regulator 12. The first regulator 11 and the second regulator 12 are voltage stabilizing circuits. The first regulator 11 converts the stable voltages VC1 and VC3 from the power supply voltage Ein supplied from the power supply 3.
Generate The second regulator 12 generates a stable voltage VC2 from the power supply voltage Ein supplied from the power supply 3. The power supply 3 is composed of a battery or a personal computer power supply.

The high-frequency circuit section 2 includes a local oscillation section 21, a transmission section 22, and a reception section 23. The local oscillator 21
The stable voltage VC1 is supplied from the first regulator 11, and oscillates at constant frequencies fr and ft.

The transmission section 22 includes a transmission circuit 221 and a power amplification circuit 222. The transmission circuit 221 includes the local oscillator 2
The transmission signal T0 is generated based on the oscillation frequency ft supplied from 1. The power amplifying circuit 222 is supplied with the stable voltage VC2 from the second regulator 12, and outputs the transmission signal T0
And outputs an amplified transmission signal T1. The amplified transmission signal T1 is supplied to the antenna 5 via the antenna sharing device 4 in the transmission slot, and is radiated in the air.

The receiving section 23 converts the received signal R1 into an intermediate frequency signal R0 using the oscillation frequency fr supplied from the local oscillating section 21.

The following embodiment will be described on the assumption that the PHS is used.

In a digital radio communication apparatus driven by the TDMA system, first, in a transmission slot in which the transmission unit 22 operates, the transmission unit 22 uses the oscillation frequency ft supplied from the local oscillation unit 21 to transmit the transmission signal T0. Combine.
As a specific example, the transmission signal T0 used in the PHS
Is in the 1900 MHz band. The transmitting unit 22 uses the oscillation frequency supplied from the local oscillation unit 21 to perform PHS
1900 MHz band transmission signal T0 used in
Are synthesized.

The transmission signal T0 is supplied to the power amplification circuit 222
, And is further supplied to the antenna 5 through the antenna duplexer 4 and radiated into the air. The power amplifying circuit 222 has, for example, an output of 100 m as described above.
W, the current consumption is about 200 mA, and the power consumption is particularly large as compared with other components such as the receiving unit 23.

Next, in the reception slot in which the receiver 23 operates, the antenna 5 and the antenna duplexer 4
To the receiving signal R1. The frequency of the received signal R1 is
In PHS, it is the 1900 MHz band. The receiving unit 23 uses the oscillation frequency fr supplied from the local oscillation unit 21 to
Finally, an intermediate frequency of 10.8 MHz required by the signal processing unit 6 is synthesized. The 10.8 MHz intermediate frequency signal is processed in the signal processing unit 6 and further supplied to the interface unit 7. Interface section 7
Is provided with a microphone, a speaker, and the like.

In the reception slot, the power amplification circuit 222 of the transmission section 22 is not operating, so that the power amplification circuit 222
No current flows through. Therefore, a current fluctuation of about 200 mA occurs between the transmission slot and the reception slot, and the voltage fluctuates. Conventionally, the operating power is supplied from the same power supply unit to the power amplification circuit 222 and the local oscillation unit 21.
When a voltage change caused by the OFF operation occurs, the voltage supplied to the local oscillator 21 also changes, and there is a problem that the oscillation frequency of the local oscillator 21 changes.

In the present invention, the voltage stabilizer 1
The first regulator 1 includes a first regulator 1 and a second regulator 12.
1 supplies a stable voltage, and supplies the power amplifier circuit 222 with a stable voltage VC2 from the second regulator 12. Therefore, even if a voltage fluctuation occurs between the transmission slot and the reception slot due to ON / OFF of the power amplification circuit 222, the voltage fluctuation is caused by the second regulator supplying the stable voltage VC2 to the power amplification circuit 222. 12, the influence on the first regulator 11 that supplies the stable voltage VC1 to the local oscillator 21 is small. That is, from the first regulator 11 to the local oscillator 21
Does not fluctuate greatly even when the power amplifier circuit 222 performs an on / off operation. For this reason, the oscillation frequencies fr and ft of the local oscillator 21
Is kept constant. Further, it is possible to transmit with high-precision modulation and receive with low bit error rate.

In the embodiment shown in FIG. 1, the stable voltage VC3 is supplied from the first regulator 11 to the transmission circuit 221 and the reception unit 23 in the high-frequency circuit unit 2.
However, a circuit configuration for supplying the stable voltage VC3 from the second regulator 12 to the transmission circuit 221 and the reception unit 23 may be used.

In the digital radio communication apparatus shown in FIG. 1, the voltage stabilizer 1 and the high-frequency circuit 2 are combined with other circuit parts, for example, the antenna duplexer 4, the antenna 5, the signal processing unit 6, and the interface unit 7 in circuit form. Alternatively, a structure that is mechanically integrated can be adopted.

Further, as another mode, the voltage stabilizer 1, the high-frequency circuit 2, and the antenna duplexer 4 are replaced with other circuit parts,
For example, it may be separated from the antenna 5, the signal processing unit 6, and the interface unit 7 and made into components as a high-frequency unit. In FIG. 1, a square 100 indicated by a dotted line
Indicates an area made into a component as a high-frequency unit. By preparing such a high-frequency unit 100, a power supply 3
81, terminals 82 and 83 for connecting the signal processing unit 6, and a terminal 83 for connecting the antenna 5
By providing the above, the digital wireless communication device can be easily assembled.

FIG. 2 is a more specific circuit diagram of the high-frequency unit of the digital wireless communication apparatus shown in FIG. The local oscillator 21 includes a reference oscillator 210 and a first oscillator 21
1 and a second oscillator 212. The first oscillator 211 generates a signal of the frequency f1 from the reference frequency f0 supplied from the reference oscillator 210. The second oscillator 212 has a reference frequency f supplied from the reference oscillator 210.
From 0, a signal of frequency f2 is generated. In the case of PHS, the frequency f1 generated by the first oscillator 211 is, for example, 233.15 MHz, and the frequency f2 generated by the second oscillator 212 is in the 1660 MHz band.

The transmitting circuit 221 of the transmitting section 22 includes the modulator 2
23, a low-pass filter 224, a frequency converter (mixer) 225, and a band-pass filter 226. The modulator 223 quadrature-modulates the signal supplied from the signal processing unit 6 (see FIG. 1) with the signal of the frequency f1 supplied from the first oscillator 211. The modulated signal output from the modulator 223 is supplied to the frequency converter 225 through the low-pass filter 224.

The frequency converter 225 includes the second oscillator 2
12, a signal of frequency f2 is supplied, and the signal of frequency f2 and the modulation signal supplied from modulator 223 synthesize a specific frequency of the 1900 MHz band. The transmission signal T of the frequency thus synthesized
0 is supplied to the transmission amplifier circuit 222 via the band-pass filter 226 and amplified. Then, it is supplied to the antenna 5 via the antenna duplexer 4 and transmitted in the air.

The receiving unit 23 includes a low noise amplifier circuit 231
, A band-pass filter 232, a frequency converter (mixer) 234, a band-pass filter 235, a frequency converter (mixer) 236, and a limiter amplifier circuit 237.

In the receiving slot, 190 supplied to the receiving section 23 through the antenna 5 and the antenna duplexer 4
The received signal R1 in the 0 MHz band is supplied to the low noise amplifier circuit 231.
, And supplied to the frequency converter 234 through the band-pass filter 232. Frequency converter 2
The signal of the frequency f2 is supplied to the 34 from the second oscillator 212, and a frequency of, for example, 243.95 MHz is synthesized. The signal of the frequency synthesized in this manner is supplied to the frequency converter 236 via the band pass filter 235.

The frequency converter 236 includes the first oscillator 2
11, a signal having a frequency f1 is supplied. Specifically, a frequency of 10.8 MHz is synthesized.

The 10.8 MHz generated in this way
Is amplified through the limiter amplifier circuit 237 and supplied to the signal processing unit 6.

FIG. 3 is a block diagram showing another embodiment of the digital radio communication apparatus according to the present invention. In the figure, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. In this embodiment, the voltage stabilizing section 1 further includes a third regulator 13. The third regulator 13 is provided to the transmission unit 22 and the reception unit 23 except for the power amplification circuit 222.
Supplies a stable voltage VC3. With respect to the local oscillator 21, the stable voltage VC1 is supplied from the first regulator 11, which is a circuit different from the second regulator 12 and the third regulator 13. For the signal processing unit 6,
It is desirable to supply a stable voltage VC2 from the second regulator 12 via the terminal 85.

According to such a configuration, when the clock frequency of the signal processing unit 6 is increased (increased) by the ripple rejection characteristic of the regulator, the local oscillating unit 21 is protected from the noise generated thereby. , The accuracy of the oscillation frequency can be maintained.

FIG. 4 is a block diagram showing another embodiment of the digital radio communication apparatus according to the present invention. In the drawings, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals. In this example,
The first regulator 11 employs a circuit configuration in which the stable voltage VC3 supplied from the third regulator 13 is further stabilized and supplied to the local oscillator 21.

According to this configuration, the voltage fluctuation is completely eliminated, and the local oscillation unit 21 is completely removed from the voltage fluctuation and various kinds of noise accompanying the TDMA system since the rejection characteristic is 80 to 100 dB. Protect
The accuracy of the oscillation frequency can be maintained. Further, even when a personal computer power supply having poor noise characteristics is used as the power supply 3, the local oscillator 21 can be protected from noise coming from the personal computer power supply, and the accuracy of the oscillation frequency can be maintained.

[0050]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a digital radio communication device and a high-frequency unit capable of maintaining an oscillation frequency of a local oscillation unit at a constant. (B) It is possible to provide a digital radio communication device and a high-frequency unit that can transmit with high-precision modulation and receive with a low bit error rate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a digital wireless communication apparatus according to the present invention.

FIG. 2 is a more specific circuit diagram of a high-frequency unit of the digital wireless communication device shown in FIG.

FIG. 3 is a block diagram showing another embodiment of the digital wireless communication apparatus according to the present invention.

FIG. 4 is a block diagram showing still another embodiment of the digital wireless communication apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Voltage stabilizer 11 First regulator 12 Second regulator 13 Third regulator 2 High frequency circuit part 21 Local oscillation part 22 Transmitter 23 Receiver 222 Power amplifier circuit

Claims (14)

[Claims] 1. A digital wireless communication device including a voltage stabilizing unit and a high-frequency circuit unit, wherein the voltage stabilizing unit includes a first regulator and a second regulator, and includes a power source supplied from a power source. Generating a stable voltage from a voltage, the high-frequency circuit unit includes a local oscillator, a transmitter, and a receiver; the local oscillator is supplied with a stable voltage from the first regulator, and has a constant frequency. The transmission unit includes a power amplification circuit, generates a transmission signal using an oscillation frequency supplied from the local oscillation unit, and the power amplification circuit receives a stable voltage from the second regulator. The digital wireless communication device amplifies the transmission signal, and the receiving unit converts the received signal to an intermediate frequency signal using an oscillation frequency supplied from the local oscillation unit. 2. The digital wireless communication device according to claim 1, wherein the transmitting unit and the receiving unit excluding the power amplifying circuit receive a stable voltage from the first regulator. . 3. The digital wireless communication device according to claim 1, wherein the transmitting unit and the receiving unit excluding the power amplifying circuit receive a stable voltage from the second regulator. . 4. The digital wireless communication apparatus according to claim 1, wherein the voltage stabilizing unit further includes a third regulator, and the transmitting unit and the receiving unit excluding the power amplifying circuit A digital wireless communication device receiving a stable voltage from the third regulator; 5. The digital wireless communication device according to claim 4, wherein the first regulator further stabilizes a stable voltage supplied from the third regulator and supplies the stabilized voltage to the local oscillator. Digital wireless communication device. 6. The digital wireless communication device according to claim 1, wherein the voltage stabilizer is supplied with a power supply voltage from a computer power supply. 7. The digital wireless communication apparatus according to claim 1, further comprising a signal processing unit, wherein the signal processing unit is supplied with a stable voltage from the second regulator, and supplies the stable voltage to the transmission unit. A digital wireless communication device that supplies a signal and receives the intermediate frequency signal from the receiving unit. 8. A voltage stabilizing unit, comprising: a high-frequency circuit unit;
A high-frequency unit used in a digital wireless communication device, wherein the voltage stabilizer includes a first regulator and a second regulator, and generates a stable voltage from a power supply voltage supplied from a power supply. The unit includes a local oscillation unit, a transmission unit, and a reception unit. The local oscillation unit is supplied with a stable voltage from the first regulator, oscillates at a constant frequency, and the transmission unit includes a transmission circuit and A power amplification circuit, wherein the transmission circuit generates a transmission signal using an oscillation frequency supplied from the local oscillation unit, wherein the power amplification circuit is supplied with a stable voltage from the second regulator, A high-frequency unit for amplifying a transmission signal, wherein the reception unit converts the reception signal into an intermediate frequency signal using an oscillation frequency supplied from the local oscillation unit. 9. The high-frequency unit according to claim 8, wherein the transmission unit and the reception unit excluding the power amplification circuit are supplied with a stable voltage from the first regulator. 10. The high-frequency unit according to claim 8, wherein the transmission unit and the reception unit except for the power amplification circuit are supplied with a stable voltage from the second regulator. 11. The high-frequency unit according to claim 8, wherein the voltage stabilizing unit further includes a third regulator, and the transmitting unit and the receiving unit excluding the power amplifying circuit, A high-frequency unit to which a stable voltage is supplied from a third regulator. 12. The high-frequency unit according to claim 11, wherein the first regulator further stabilizes a stable voltage supplied from the third regulator and supplies the stabilized voltage to the local oscillator. . 13. The high-frequency unit according to claim 8, wherein the voltage stabilizer is supplied with a power supply voltage from a computer power supply. 14. A digital wireless communication device having a high-frequency unit, wherein the high-frequency unit is any one of claims 8 to 13.