JP2000022592A - Transmitter-receiver, modulation control method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb variance in DC component level that is caused in a demodulator to keep a constant time when an AGC level is fixed and also to secure a fixed quantity of data which can be transmitted in a single packet by inversely spreading a spread modulating signal by means of a diffusion code and controlling the extracted carrier component. SOLUTION: An inverse spread demodulator 116 supplies a signal S106 of only a carrier component obtained by eliminating the spread code component from a spread modulating signal S109 to a carrier level detector 113. The detector 113 detects a carrier level based on the output of the demodulator 116. A control part 114 produces a control signal S107 via a carrier level control signal generator 115 to decrease the carrier leak value when the leak value outputted from the modulators 105 and 106 are larger than a fixed level. If these leak value are smaller than a fixed level, the part 114 generates the reference voltage to increase the carrier leak value and controls the carrier leak value at a fixed level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception apparatus, a modulation control method, and a storage medium, and more particularly to a quadrature phase modulation / demodulation method for digital radio communication (modulation / demodulation for transmitting / receiving digital information using mutually orthogonal waveforms) The present invention relates to a transmission / reception device, a modulation control method, and a storage medium that are suitable when using (method).

[0002]

2. Description of the Related Art Conventionally, there has been a transmission / reception apparatus using a quadrature phase modulation / demodulation system. FIG. 3 is a block diagram showing a schematic configuration of a modulation section of a quadrature phase modulation / demodulation system according to a conventional example.
Conventional modulators include D / A converters 301 and 302, LPF
(Low-pass filter) 303, 304, modulator 305,
306, a carrier generator 307, a 90-degree phase shifter 308,
An adder 309 and an amplifier 310 are provided. Primary spread modulated signals S301 and S30 from a digital processing unit (not shown)
2 is supplied to D / A converters 301 and 302 and converted into analog signals, respectively, and then subjected to a desired band limitation via LPFs 303 and 304 having a pass band of a signal band of the spread modulation signal, and a carrier generator A secondary modulation operation is performed on the carrier signals S303 and S304 from 307 using the modulators 305 and 306 to generate a spread modulation signal.

In the spread modulation signal, a carrier signal component input to the LO terminals of the modulators 305 and 306 without being completely suppressed is mixed as an LO leak. Here, S306 indicates a reference voltage for adjusting the level of the carrier signal component leaking to the outputs of the modulators 305 and 306 in a series of modulation operations. The respective spread modulation outputs are combined by an adder 309, supplied to a subsequent frequency converter (not shown) via an amplifier 310, converted into a radio frequency, and radiated into the air via an antenna. Here, 90 between the carrier signals S303 and S304.
The phase shifter 308 gives a phase shift difference of 90 degrees.

FIG. 4 is a block diagram showing a schematic configuration of a baseband demodulator of a conventional quadrature phase modulation / demodulation system. The conventional baseband demodulation unit includes a variable gain amplifier 4
00, splitter 401, detectors 402 and 403, carrier generator 404, 90-degree phase shifter 405, LPF 406,
07, and A / D converters 408 and 409. A reception signal from an antenna end (not shown) is down-converted in an RF front-end section and a desired IF signal S4
00 and the variable gain amplifier 4 in the IF stage.
At 00, the signal is appropriately amplified or attenuated according to the received signal level, and is supplied to the splitter 401 as a fixed level received signal S401. The received signal S401 is divided into two by a splitter 401, and carrier signals S402 and S40 from a carrier generator 404 are detected in detectors 402 and 403.
3 and is converted into a baseband signal.

[0005] A 90-degree phase shifter 405 gives a 90-degree phase difference between the carrier signals S402 and S403. The detected baseband signals are subjected to LPFs 406 and 407 having respective signal bands as passbands to remove out-of-band components, and A / D converters 408 and 40 are used.
9 and is sampled by a sampling clock signal S406 extracted from the received signal by a digital correlator or the like in a synchronization circuit unit (not shown) to become digital signals S404 and S405, which are supplied to a subsequent digital processing unit. Demodulated as data.

[0006]

However, in the above-described conventional example, the carrier component mixed in the received signal and the carrier signal from the carrier generator 404 at the stage of demodulation to the baseband have the same frequency. Therefore, a DC component is generated from the outputs of the detectors 402 and 403 in addition to the demodulated baseband signal and the multiplied wave of the carrier component. The level of this DC component is
5 and 306 depends on the magnitude of the carrier leak component. As a result, when the carrier leak amount is large, the DC component becomes large, and the A / D converters 408 and 409 at the subsequent stages mistakenly recognize the magnitude of the signal component including the DC component, and the normal received signal level is reduced. It cannot be judged. In addition, since the demodulated baseband signal contains a spreading code, it is required that the LPF at the subsequent stage, the coupling capacitor of the signal line, and the like pass the DC component as much as possible. For this reason, it takes a certain amount of time for the generated DC component to completely settle down to the GND level, depending on the amount of the generated DC component, and it becomes impossible to determine the level of the received signal during that time.

As a result, AGC (Automatic
The time until the original received signal level is determined by Gain Control (automatic gain control) and the AGC operation ends is different depending on the amount of carrier leak.
There is a problem that the amount of data transmission is also limited by the time. However, in the above-described conventional example, there is a problem that it is difficult to secure a constant level of the carrier leak amount because the carrier leak amount of the modulator varies depending on the IC, power supply fluctuation, temperature fluctuation, and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can absorb variations in the level of a DC component generated in a demodulator, maintain a fixed time for the AGC level, and transmit the signal within one packet. It is an object of the present invention to provide a transmission / reception device, a modulation control method, and a storage medium capable of keeping a possible data amount constant.

[0009]

According to a first aspect of the present invention, there is provided a transmission / reception apparatus for performing spread spectrum communication, comprising: despreading a spread modulation signal with a spread code; , A despreading means for extracting a carrier component from the signal, a detection means for detecting a carrier level, and a control means for controlling a carrier component contained in the spread modulation signal.

To achieve the above object, the present invention according to claim 2 has reference voltage generating means for outputting a reference voltage to a modulator, wherein the control means controls the carrier level detected by the detecting means. And controlling the reference voltage generating means based on the reference voltage so that the carrier component contained in the spread modulation signal becomes a constant amount.

According to another aspect of the present invention, there is provided a reference voltage generating means for outputting a reference voltage to a modulator, and a control signal according to a carrier level detected by the detecting means. Control signal generation means, wherein the control means generates a control signal by the control signal generation means based on the carrier level detected by the detection means, controls the reference voltage generation means, and is included in the spread modulation signal. It is characterized in that the carrier component is controlled to be a constant amount.

According to a fourth aspect of the present invention, the control means generates a control signal by the control signal generation means when the carrier level detected by the detection means is larger than a predetermined amount. Then, a reference voltage is output from the reference voltage generation means to the modulator so as to reduce the carrier component. If the carrier level detected by the detection means is smaller than a certain amount, a control signal is generated by the control signal generation means. Then, control is performed to output a reference voltage from the reference voltage generation means to the modulator so as to increase a carrier component.

In order to achieve the above object, the present invention according to claim 5 is characterized in that the control means performs control for cutting off a primary modulation signal at the start of transmission.

In order to achieve the above object, the present invention according to claim 6 is characterized in that it is applicable to spread spectrum communication using a quadrature phase modulation / demodulation system.

According to another aspect of the present invention, there is provided a modulation control method applied to a transmission / reception apparatus for performing spread spectrum communication, comprising: despreading a spread modulation signal with a spread code to perform spread modulation. The method includes a despreading step of extracting a carrier component from a signal, a detecting step of detecting a carrier level, and a control step of controlling a carrier component contained in the spread modulation signal.

In order to achieve the above object, the present invention according to claim 8 has a reference voltage generating step of outputting a reference voltage to a modulator. And controlling the reference voltage generation step based on the reference voltage generation step so that the carrier component contained in the spread modulation signal becomes a constant amount.

To achieve the above object, according to the present invention, a reference voltage generating step for outputting a reference voltage to a modulator and a control signal corresponding to a carrier level detected in the detecting step are generated. Control signal generation step, wherein in the control step, a control signal is generated in the control signal generation step based on the carrier level detected in the detection step, and the reference voltage generation step is controlled to be included in the spread modulation signal. It is characterized in that the carrier component is controlled to be a constant amount.

According to a tenth aspect of the present invention, in the control step, a control signal is generated in the control signal generation step when the carrier level detected in the detection step is larger than a predetermined amount. Then, a reference voltage is output from the reference voltage generation step to the modulator so as to reduce the carrier component. If the carrier level detected in the detection step is smaller than a predetermined amount, a control signal is generated in the control signal generation step. Then, control is performed to output a reference voltage from the reference voltage generation step to the modulator so as to increase a carrier component.

In order to achieve the above object, the present invention as set forth in claim 11 is characterized in that in the control step, control is performed to cut off the primary modulation signal at the start of transmission.

In order to achieve the above object, the present invention is characterized in that the present invention is applicable to spread spectrum communication using a quadrature phase modulation / demodulation system.

To achieve the above object, the present invention according to claim 13 is a storage medium readable by a computer storing a program for executing a modulation control method applied to a transmission / reception apparatus for performing spread spectrum communication. The modulation control method includes the steps of: despreading a spread modulation signal based on a spread code to extract a carrier component from the spread modulation signal; detecting a carrier level; and detecting a carrier contained in the spread modulation signal. And a control step of controlling the components.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

[1] First Embodiment FIG. 1 shows a spread spectrum communication system using a quadrature phase modulation / demodulation system according to a first embodiment of the present invention (the minimum required for transmitting information to be transmitted). FIG. 3 is a block diagram illustrating a configuration of a modulation unit of a transmission / reception apparatus according to a communication scheme in which a signal is spread and transmitted in a frequency band much wider than a limit frequency bandwidth. The modulation unit of the transmitting and receiving apparatus according to the first embodiment of the present invention includes a D / A converter 101, a D / A converter 102,
LPF103, LPF104, modulator 105, modulator 1
06, a carrier generator 107, a 90-degree phase shifter 108, a reference voltage generator 109, an adder 111, an amplifier 112, a carrier level detector 113, a control unit 114, a carrier level control signal generator 115, and a despread demodulator 116. , PN
The configuration includes a code generator 117.

The D / A converter 101 converts a digital signal S101 from a digital processing unit (not shown) into an analog signal. The D / A converter 102 receives the digital signal S102 from the digital processing unit.
To an analog signal. The LPF 103 subjects the output of the D / A converter 101 to a desired band limitation. LPF
104 performs a desired band limitation on the output of the D / A converter 102. The modulator 105 performs spread modulation on the output of the LPF 103 based on the carrier signal S103 from the carrier generator 107. The modulator 106 includes the LPF 104
Is spread-modulated with respect to the output based on the carrier signal S104 from the carrier generator 107.

The carrier generator 107 outputs the carrier signal S
103 and S104 are generated. The 90 degree phase shifter 108
A phase difference of 90 degrees is provided between the carrier signals S103 and S104. The reference voltage generator 109 includes a modulator 105,
A reference voltage is generated for the carrier 106 in a direction to reduce the amount of carrier leakage. The adder 111 adds the outputs from the modulators 105 and 106. The amplifier 112 includes an adder 111
Amplify the output. The carrier level detector 113 detects a carrier level based on the output of the despread demodulator 116.

The control unit 114 controls the carrier level control signal generator 115 to generate the control signal S107 in order to reduce the amount of carrier leakage when the amount of carrier leakage output from the modulators 105 and 106 is larger than a certain amount. I do. When the carrier leak amount detected by the carrier level detector 113 is smaller than a certain amount, the control unit 114 generates a reference voltage in a direction to increase the carrier leak amount so that the carrier leak amount becomes constant. Control the reference voltage. The carrier level control signal generator 115 generates the control signal S107 based on the control of the control unit 114. The despread demodulator 116 supplies the carrier level detector 113 with a signal S106 of only the carrier component obtained by removing the spread code component from the spread modulation signal S109. The PN code generator 117 outputs a PN code (Pseu).
de Noise code (pseudo noise code) is supplied to the despread demodulator 116.

In this case, the correspondence between the above-described parts in the first embodiment of the present invention and the respective constituent elements in the claims is as follows. The modulators 105 and 106 correspond to modulators, the reference voltage generator 109 corresponds to reference voltage generation means, the carrier level detector 113 corresponds to detection means, the control unit 114 corresponds to control means, and the carrier level The control signal generator 115 corresponds to the control signal generator, and the despread demodulator 116 corresponds to the despreader.

Next, the first embodiment of the present invention configured as described above is described.
The operation of the modulation section of the transmitting / receiving apparatus according to the embodiment will be described. Digital signal S1 from a digital processing unit (not shown)
01 and S102 are D / A converters 101 and 10 respectively.
2 and converted to an analog signal, the LPF 10
The signal is subjected to a desired band limitation via the third and third channels 104 and spread and modulated by the carrier signals S103 and S104 from the carrier generator 107 and the modulators 105 and 106. Each spread modulated signal is synthesized by an adder 111 and an amplifier 112
, Is supplied to a subsequent frequency converter (not shown), is converted into a radio frequency, and is radiated into the air via an antenna. A 90-degree phase shifter 108 gives a 90-degree phase difference between the carrier signals S103 and S104.

Here, the modulators 105 and 106 leak the carrier component from the carrier generator 107 to the output as a carrier leak amount. The level changes according to the output voltage from the reference voltage generator 109. The carrier leak component output from the modulators 105 and 106 is added to the adder 11 similarly to the spread modulation signal component.
After being added by 1, the signal is supplied to a subsequent-stage frequency converter (not shown) via the amplifier 112, converted into a radio frequency, and then radiated into the air via an antenna.

In order to keep the amount of carrier leakage output from the modulators 105 and 106 constant, the amplifier 112
The spread modulation signal S109, which is the output of
6 and the other input terminal of the despread demodulator 116 has a PN
The PN code output from the code generator 117 is input.
Here, the PN code output from the PN code generator 117 is an input signal S101 that has been subjected to primary modulation by data.
PN having the same sign as S102 and having the same phase
Sign. Therefore, the output signal S of the despread demodulator 116
Reference numeral 106 denotes only a carrier component obtained by removing the spread code component from the spread modulation signal S109. Despread demodulator 116
Is supplied to the carrier level detector 113, and the detected amount is supplied to the control unit 114.

In the control unit 114, the modulators 105 and 106
If the amount of carrier leak output from is larger than a certain amount, the control signal S is sent to the carrier level control signal generator 115 so as to reduce the amount of carrier leak.
In response to the control signal S107, the reference voltage generator 109 causes the modulators 105 and 106 to generate a reference voltage in a direction to reduce the amount of carrier leakage. On the other hand,
When the carrier leak amount detected by the carrier level detector 113 is smaller than a certain amount, the control unit 114 generates a reference voltage in a direction to increase the carrier leak amount, and sets the reference voltage so that the carrier leak amount becomes constant. Control.

As described above, according to the modulation section of the transmitting and receiving apparatus according to the first embodiment of the present invention, the PN code generator 117 for supplying the PN code to the despread demodulator 116.
And a despread demodulator 116 that supplies a carrier level detector 113 with only a carrier component signal S106 obtained by removing a spread code component from the spread modulation signal S109, and a carrier that detects a carrier level based on the output of the despread demodulator 116 When the carrier leak amount output from the level detector 113 and the modulators 105 and 106 is larger than a certain amount, a control signal S107 is generated from the carrier level control signal generator 115 to reduce the carrier leak amount,
When the carrier leak amount detected by the carrier level detector 113 is smaller than a certain amount, a reference voltage is generated in a direction to increase the carrier leak amount, and the reference voltage is controlled so that the carrier leak amount becomes constant. Part 11
4, a carrier level control signal generator 115 for generating a control signal S107 based on the control of the control unit 114, and a reference for generating a reference voltage for the modulators 105 and 106 in a direction to reduce the amount of carrier leakage based on the control signal S107. The presence of the voltage generator 109 provides the following operation and effects.

In the above configuration, the carrier leak amount output from the modulator is detected by the carrier level detector 113, and the control unit 114 sets the carrier leak amount to a certain amount according to the detected carrier leak amount. A carrier leak level control signal is generated, and a reference voltage generator 109 is generated according to the carrier leak level control signal.
, The amount of carrier leak output from the modulators 105 and 106 can be made constant. This makes it possible to absorb the variation in the level of the DC component generated in the demodulator, to keep the time for determining the AGC level constant, and to make the amount of data that can be transmitted in one packet constant. There is an effect.

[2] Second Embodiment FIG. 2 is a block diagram showing a configuration of a modulation unit of a transmission / reception apparatus using a spread spectrum communication system using a quadrature phase modulation / demodulation system according to a second embodiment of the present invention. is there. The modulating unit of the transmitting / receiving device according to the second embodiment of the present invention includes a D / A converter 201, a D / A converter 202, an LPF 203,
F204, modulator 205, modulator 206, carrier generator 207, 90-degree phase shifter 208, reference voltage generator 20
9, an adder 211, an amplifier 212, a carrier level detector 213, a control unit 214, and a carrier level control signal generator 215.

The D / A converter 201 converts a digital signal S201 from a digital processing unit (not shown) into an analog signal. The D / A converter 202 receives the digital signal S202 from the digital processing unit.
To an analog signal. The LPF 203 subjects the output of the D / A converter 201 to a desired band limitation. LPF
A 204 limits the output of the D / A converter 202 to a desired band. The modulator 205 performs spread modulation on the output of the LPF 203 based on the carrier signal S203 from the carrier generator 207. The modulator 206 includes the LPF 204
Is spread-modulated based on the carrier signal S204 from the carrier generator 207.

The carrier generator 207 outputs the carrier signal S
203 and S204 are generated. The 90 degree phase shifter 208
A phase shift of 90 degrees is provided between the carrier signals S203 and S204. The reference voltage generator 209 includes a modulator 205,
A reference voltage is generated in the direction to reduce the amount of carrier leakage with respect to 206. The adder 211 adds the outputs from the modulators 205 and 206. The amplifier 212 includes an adder 211
Amplify the output. The carrier level detector 213 detects a carrier level based on the output of the amplifier 212.

The control unit 214 controls the carrier level control signal generator 215 to generate a control signal S207 to reduce the amount of carrier leakage when the amount of carrier leakage output from the modulators 205 and 206 is larger than a certain amount. I do. Further, when the carrier leak amount detected by the carrier level detector 213 is smaller than a certain amount, the control unit 214 generates a reference voltage in a direction to increase the carrier leak amount so that the carrier leak amount becomes constant. Control the reference voltage. Further, the control unit 214 turns off the primary modulation signals S201 and S202 at the start of transmission, and supplies the primary modulation signals S201 and S202 to the modulators 205 and 206 when the carrier leakage amount reaches a certain amount. A control signal S210 for turning on the A converters 201 and 202 is output. The carrier level control signal generator 215 generates the control signal S207 under the control of the control unit 214.

In this case, the correspondence between the components in the second embodiment of the present invention and the components in the claims is as follows. The modulators 205 and 206 correspond to modulators, the reference voltage generator 209 corresponds to reference voltage generation means, the carrier level detector 213 corresponds to detection means, the control unit 214 corresponds to control means, and the carrier level The control signal generator 215 corresponds to a control signal generator.

Next, the second embodiment of the present invention constructed as described above
The operation of the modulation section of the transmitting / receiving apparatus according to the embodiment will be described. Digital signal S2 from a digital processing unit (not shown)
01 and S202 are D / A converters 201 and 20 respectively.
2 and is converted to an analog signal.
3 and 204, the signal is subjected to a desired band limitation, and a reference signal (carrier signal) S203 from the carrier generator 207 is received.
Spread modulation is performed by S204 and modulators 205 and 206. Each spread-modulated signal is synthesized by an adder 211 and passes through an amplifier 212 to a frequency conversion unit (not shown) at a subsequent stage.
And is converted to radio frequency and then radiated into the air via an antenna. Carrier signals S203 and S204
And a 90-degree phase shifter 208 gives a 90-degree phase shift difference.

Here, the modulators 205 and 206 leak the carrier component from the carrier generator 207 to the output as carrier leak. The level changes according to the output voltage from the reference voltage generator 209. The carrier components output from the modulators 205 and 206 are added by the adder 211 in the same manner as the spread modulation signal component, and supplied to a subsequent frequency converter (not shown) via the amplifier 212 to be converted into a radio frequency. Later, it is radiated into the air via an antenna.

Here, the second embodiment of the present invention is different from the first embodiment in that the control signal S for turning off the primary modulation signals S201 and S202 at the start of transmission.
210. That is, by cutting off the primary modulation signal from the signal line, the spread signal output to the modulators 205 and 206 can be made only of the carrier leak component. Therefore, in order to keep the carrier leak amount output from the modulators 205 and 206 constant, the output signal S209 of the amplifier 212 is supplied to the carrier level detector 213, and the detected amount is supplied to the control unit 214.

In the control section 214, the modulators 205 and 206
If the amount of carrier leak output from is larger than a certain amount, the control signal S is sent to the carrier level control signal generator 215 so as to reduce the amount of carrier leak.
207, and upon receiving the control signal S207, the reference voltage generator 209 causes the modulators 205 and 206 to generate a reference voltage in a direction to reduce the amount of carrier leakage. On the other hand,
When the amount of carrier leak detected by the carrier level detector 213 is smaller than a certain amount, the control unit 214 generates a reference voltage in a direction to increase the amount of carrier leak, and controls the reference voltage so that the amount of carrier leak becomes constant. Control. Therefore, when the carrier leak amount becomes a certain amount, the control unit 214 supplies the primary modulation signals to the modulators 205 and 206 from the D / A converters 201 and 202.
A control signal S210 for turning ON is transmitted.

As described above, according to the modulation section of the transmitting and receiving apparatus according to the second embodiment of the present invention, the amplifier 21
2 and a carrier level control signal generator for reducing the amount of carrier leakage when the amount of carrier leakage output from the modulators 205 and 206 is larger than a certain amount. 215 to generate a control signal S207;
If the amount of carrier leakage detected by the carrier level detector 213 is smaller than a certain amount, a reference voltage is generated in a direction to increase the amount of carrier leakage, and the reference voltage is controlled so that the amount of carrier leakage becomes constant. At the start of transmission, the primary modulation signals S201 and S202 are turned off, and when the carrier leak amount becomes a certain amount, the D / A converters 201 and 202 are supplied to supply the primary modulation signals S201 and S202 to the modulators 205 and 206. Control signal S to be turned ON
A control unit 214 that outputs a signal 210, a carrier level control signal generator 215 that generates a control signal S207 based on the control of the control unit 214, and a modulator 205, 206 that reduces the amount of carrier leakage based on the control signal S207. Because of the provision of the reference voltage generator 209 for generating the reference voltage, the following operations and effects are achieved.

In the above configuration, the carrier leak amount output from the modulator is detected by the carrier level detector 213, and the control unit 214 sets the carrier leak amount to a certain amount according to the detected carrier leak amount. A carrier leak level control signal is generated, and a reference voltage generator 209 is generated according to the carrier leak level control signal.
, The amount of carrier leak output from the modulators 205 and 206 can be made constant. This makes it possible to absorb the variation in the level of the DC component generated in the demodulator, to keep the time for determining the AGC level constant, and to make the amount of data that can be transmitted in one packet constant. There is an effect.

In the transmitting and receiving apparatuses according to the first and second embodiments of the present invention described above, the control unit 114 (21
The modulators 105 and 106 are constituted by the configuration centered on 4).
Although the control for making the amount of carrier leak output from (205, 206) constant was performed, a computer-readable storage medium storing a program for executing the modulation control method applied to the transmission / reception apparatus of the present invention uses: The computer reads the program and supplies the program to the control unit 114 (214) of the transmitting / receiving apparatus of the present invention via the computer, whereby the control unit 114 (21)
4) It is also possible to adopt a configuration in which the above control is performed based on the above program.

The present invention may be applied to a system constituted by a plurality of devices or to an apparatus constituted by a single device. A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (or CPU or MPU) of the system or the apparatus executes the program code stored in the storage medium. Needless to say, this can also be achieved by executing the reading.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS and the like running on the computer are actually executed based on the instructions of the program code. It goes without saying that a part or all of the above-described processing is performed, and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0051]

As described above, according to the transmission / reception apparatus of the present invention, there is provided a transmission / reception apparatus for performing spread spectrum communication, which despreads a spread modulation signal with a spread code and converts the spread modulation signal from the spread modulation signal. Since it has the despreading means for extracting the carrier component, the detecting means for detecting the carrier level, and the control means for controlling the carrier component contained in the spread modulation signal, the following effects are obtained.

The carrier component (carrier leak amount) output from the modulator is detected by the detecting means, and the carrier leak amount is controlled according to the detected carrier leak amount, whereby the carrier leak amount output from the modulator is detected. Can be kept constant. This makes it possible to absorb the variation in the level of the DC component generated in the demodulator,
(Automatic gain control) There is an effect that the time for determining the level can be kept constant and the amount of data that can be transmitted in one packet can be made constant.

According to a second aspect of the present invention, there is provided a transmission / reception apparatus having reference voltage generating means for outputting a reference voltage to a modulator, wherein the control means controls the reference voltage based on the carrier level detected by the detection means. Since the voltage generation means is controlled to control the carrier component contained in the spread modulation signal to a constant amount, the following effects are obtained.

The carrier component (the amount of carrier leak) output from the modulator is detected by the detecting means, and the reference voltage of the reference voltage generating means is adjusted so as to make the amount of the carrier leak constant according to the detected amount of the carrier leak. , The amount of carrier leak output from the modulator can be made constant. This makes it possible to absorb the variation in the level of the DC component generated in the demodulator,
(Automatic gain control) There is an effect that the time for determining the level can be kept constant and the amount of data that can be transmitted in one packet can be made constant.

According to a third aspect of the present invention, there is provided a transmission / reception apparatus, comprising: a reference voltage generator for outputting a reference voltage to a modulator;
Control signal generation means for generating a control signal according to the carrier level detected by the detection means, wherein the control means generates a control signal by the control signal generation means based on the carrier level detected by the detection means The reference voltage generating means is controlled so as to control the carrier component contained in the spread modulation signal to be a fixed amount, so that the following effects are obtained.

A carrier component (a carrier leak amount) output from the modulator is detected by a detecting means, and a control signal is generated from a control signal generating means in accordance with the detected carrier leak amount so as to make the carrier leak amount a certain amount. By generating a (carrier leak level control signal) and controlling the reference voltage of the reference voltage generating means according to the carrier leak level control signal, the amount of carrier leak output from the modulator can be made constant. As a result, it is possible to absorb variations in the level of the DC component generated in the demodulator, to keep the time for determining the AGC (automatic gain control) level constant, and to keep the amount of data that can be transmitted in one packet constant. There is an effect that can be performed.

According to a fourth aspect of the present invention, when the carrier level detected by the detecting means is larger than a predetermined amount, the control means generates a control signal by the control signal generating means, and A reference voltage is output from the reference voltage generation means to the modulator so as to reduce a carrier component, and when the carrier level detected by the detection means is smaller than a certain amount, a control signal is generated by the control signal generation means. Since control is performed to output a reference voltage from the reference voltage generation means to the modulator so as to increase the carrier component, the following effects are obtained.

A carrier component (a carrier leak amount) output from the modulator is detected by a detecting means, and a control signal is generated from a control signal generating means in accordance with the detected carrier leak amount so as to make the carrier leak amount a certain amount. (Carrier leak level control signal) and controlling the reference voltage of the reference voltage generating means according to the carrier leak level control signal, that is, if the carrier leak amount is larger than a certain amount, the carrier leak amount is reduced. The reference voltage is output from the reference voltage generating means so that the reference voltage is output from the reference voltage generating means so as to increase the carrier leak amount when the carrier leak amount is smaller than a predetermined amount. , The amount of carrier leak output from the device can be made constant. As a result, it is possible to absorb variations in the level of the DC component generated in the demodulator, to keep the time for determining the AGC (automatic gain control) level constant, and to keep the amount of data that can be transmitted in one packet constant. There is an effect that can be performed.

According to the transmitting and receiving apparatus of the present invention, since the control means performs control to cut off the primary modulation signal at the start of transmission, the following effects are obtained.

In the same manner as described above, the variation in the level of the DC component generated in the demodulator can be absorbed, the time for determining the AGC (automatic gain control) level can be kept constant, and the transmission is possible within one packet. In addition to the effect that the data amount can be made constant, the primary modulation signal is cut off from the signal line at the start of transmission, so that the spread signal output to the modulator can be made only a carrier leak component. .

According to the transmission / reception apparatus of the present invention, the following effects can be obtained because the transmission / reception apparatus is applicable to spread spectrum communication using the quadrature phase modulation / demodulation method.

In the transmission / reception apparatus for performing spread spectrum communication using the quadrature phase modulation / demodulation method, in the same manner as described above, the variation in the level of the DC component generated in the demodulator can be absorbed, and the time for determining the AGC (automatic gain control) level Can be kept constant, and the amount of data that can be transmitted in one packet can be kept constant.

According to a seventh aspect of the present invention, there is provided a modulation control method applied to a transmission / reception apparatus for performing spread spectrum communication, comprising: despreading a spread modulation signal with a spread code; Since it has a despreading step of extracting a carrier component, a detecting step of detecting a carrier level, and a control step of controlling a carrier component contained in the spread modulation signal, the following effects are obtained.

A carrier component (carrier leak amount) output from the modulator is detected in a detection step, and the carrier leak amount is controlled in accordance with the detected carrier leak amount, whereby the carrier leak amount output from the modulator is detected. Can be kept constant. This makes it possible to absorb variations in the level of the DC component generated in the demodulator,
There is an effect that the time for determining the C (automatic gain control) level can be kept constant and the amount of data that can be transmitted in one packet can be kept constant.

According to the modulation control method of the present invention, there is provided a reference voltage generating step of outputting a reference voltage to a modulator, wherein the control step includes the step of: Since the reference voltage generation step is controlled so as to control the carrier component contained in the spread modulation signal to a constant amount, the following effects are obtained.

A carrier component (carrier leak amount) output from the modulator is detected in a detecting step, and the reference voltage in the reference voltage generating step is adjusted so as to make the carrier leak amount a certain amount according to the detected carrier leak amount. , The amount of carrier leak output from the modulator can be made constant. As a result, it is possible to absorb the variation in the level of the DC component generated in the demodulator,
This has the effect that the time for determining the AGC (automatic gain control) level can be kept constant and the amount of data that can be transmitted in one packet can be kept constant.

According to the modulation control method of the present invention, a reference voltage generating step for outputting a reference voltage to the modulator and a control signal for generating a control signal corresponding to the carrier level detected in the detecting step. Generating a control signal in the control signal generating step based on the carrier level detected in the detecting step, controlling the reference voltage generating step, and controlling the carrier contained in the spread modulation signal. Since the components are controlled to be constant, the following effects are obtained.

A carrier component (carrier leak amount) output from the modulator is detected in a detection step, and a control signal is generated from a control signal generation step in accordance with the detected carrier leak amount so that the carrier leak amount is set to a certain amount. By generating a (carrier leak level control signal) and controlling the reference voltage in the reference voltage generation step according to the carrier leak level control signal, the carrier leak amount output from the modulator can be made constant. As a result, it is possible to absorb variations in the level of the DC component generated in the demodulator, to keep the time for determining the AGC (automatic gain control) level constant, and to keep the amount of data that can be transmitted in one packet constant. There is an effect that can be performed.

According to the modulation control method of the present invention, in the control step, when the carrier level detected in the detection step is larger than a predetermined amount, a control signal is generated in the control signal generation step. A reference voltage is output from the reference voltage generation step so as to reduce a carrier component to the modulator, and if the carrier level detected in the detection step is smaller than a predetermined amount, a control signal is generated in the control signal generation step. Since the control for outputting the reference voltage so as to increase the carrier component to the modulator from the reference voltage generation step is performed, the following effects are obtained.

A carrier component (carrier leak amount) output from the modulator is detected in a detecting step, and a control signal is generated from a control signal generating step in accordance with the detected carrier leak amount so that the carrier leak amount becomes a certain amount. (Carrier leak level control signal) and controlling the reference voltage in the reference voltage generation step according to the carrier leak level control signal, that is, if the carrier leak amount is larger than a certain amount, the carrier leak amount is reduced. The modulator is controlled to output a reference voltage from the reference voltage generation step so that the reference voltage is output from the reference voltage generation step so as to increase the carrier leakage amount when the carrier leakage amount is smaller than a predetermined amount. , The amount of carrier leak output from the device can be made constant. This makes it possible to absorb the variation in the level of the DC component generated in the demodulator and to keep the time for determining the AGC (automatic gain control) level constant,
There is an effect that the amount of data that can be transmitted in one packet can be made constant.

According to the modulation control method of the present invention, in the control step, the control for cutting off the primary modulation signal at the start of transmission is performed, so that the following effects are obtained.

In the same manner as described above, it is possible to absorb the variation in the level of the DC component generated in the demodulator, to keep the time for determining the AGC (automatic gain control) level constant, and to allow transmission within one packet. In addition to the effect that the data amount can be made constant, the primary modulation signal is cut off from the signal line at the start of transmission, so that the spread signal output to the modulator can be made only a carrier leak component. .

According to the modulation control method of the twelfth aspect of the present invention, since it is applicable to spread spectrum communication using the quadrature phase modulation / demodulation method, the following effects are obtained.

In the transmission / reception apparatus for performing spread spectrum communication using the quadrature phase modulation / demodulation method, similarly to the above, it is possible to absorb the variation in the level of the DC component generated in the demodulator and to determine the AGC (automatic gain control) level. Can be kept constant, and the amount of data that can be transmitted in one packet can be kept constant.

According to the storage medium of the present invention, a computer-readable storage medium storing a program for executing a modulation control method applied to a transmission / reception apparatus for performing spread spectrum communication, The modulation control method includes a despreading step of despreading a spread modulation signal based on a spread code and extracting a carrier component from the spread modulation signal, a detection step of detecting a carrier level, and controlling a carrier component contained in the spread modulation signal. Therefore, the following effects can be obtained.

A carrier component (carrier leak amount) output from the modulator is detected in a detection step, and the carrier leak amount is controlled in accordance with the detected carrier leak amount, whereby the carrier leak amount output from the modulator is detected. Can be kept constant. This makes it possible to absorb variations in the level of the DC component generated in the demodulator,
There is an effect that the time for determining the C (automatic gain control) level can be kept constant and the amount of data that can be transmitted in one packet can be kept constant.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a modulation unit of a transmission / reception apparatus based on a spread spectrum communication system using a quadrature phase modulation / demodulation system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a modulation unit of a transmission / reception apparatus based on a spread spectrum communication system using a quadrature phase modulation / demodulation system according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a modulator of a quadrature phase modulation / demodulation system according to a conventional example.

FIG. 4 is a block diagram showing a configuration of a baseband demodulation unit of a quadrature phase modulation / demodulation system according to a conventional example.

[Explanation of symbols]

 101, 102, 201, 202 D / A converter 103, 104, 203, 204 LPF 105, 106, 205, 206 Modulator 107, 207 Carrier generator 108, 208 90-degree phase shifter 109, 209 Reference voltage generator 111, 211 Adder 112, 212 Amplifier 113, 213 Carrier level detector 114, 214 Controller 115, 215 Carrier level control signal generator 116 Despread demodulator 117 PN code generator

Claims (13)

[Claims] 1. A transmitting / receiving apparatus for performing spread spectrum communication, comprising: a despreading means for despreading a spread modulation signal with a spread code to extract a carrier component from the spread modulation signal; a detection means for detecting a carrier level; Control means for controlling a carrier component contained in the modulated signal. 2. A reference voltage generating means for outputting a reference voltage to a modulator, wherein said control means controls said reference voltage generating means based on a carrier level detected by said detecting means and is included in a spread modulation signal. 2. The transmission / reception apparatus according to claim 1, wherein the control is performed such that the carrier component is constant. 3. A control apparatus comprising: a reference voltage generator for outputting a reference voltage to a modulator; and a control signal generator for generating a control signal according to a carrier level detected by the detector. A control signal is generated by the control signal generation means based on the carrier level detected by the detection means, and the reference voltage generation means is controlled to control the carrier component contained in the spread modulation signal to be a constant amount. The transmitting / receiving device according to claim 1, wherein 4. The control means, when the carrier level detected by the detection means is larger than a predetermined amount, generates a control signal by the control signal generation means and transfers a carrier component from the reference voltage generation means to the modulator. A reference voltage is output so as to decrease, and when the carrier level detected by the detection means is smaller than a predetermined amount, a control signal is generated by the control signal generation means and a carrier component is transmitted from the reference voltage generation means to the modulator. The transmission / reception device according to claim 1, wherein control is performed to output a reference voltage so as to increase the value. 5. The transmission / reception apparatus according to claim 1, wherein the control unit performs control to cut off the primary modulation signal at the start of transmission. 6. The method according to claim 1, wherein the method is applicable to spread spectrum communication using a quadrature phase modulation / demodulation method.
The transmitting / receiving device according to any one of claims 1 to 5, wherein 7. A modulation control method applied to a transmission / reception apparatus for performing spread spectrum communication, comprising: a despreading step of despreading a spread modulation signal with a spread code and extracting a carrier component from the spread modulation signal; A modulation control method comprising: a detection step of detecting; and a control step of controlling a carrier component contained in a spread modulation signal. 8. A reference voltage generating step of outputting a reference voltage to a modulator, wherein in the control step, the reference voltage generating step is controlled based on a carrier level detected in the detecting step, and is included in a spread modulation signal. 8. The modulation control method according to claim 7, wherein the control is performed such that the number of carrier components is constant. 9. A reference voltage generating step of outputting a reference voltage to a modulator, and a control signal generating step of generating a control signal according to a carrier level detected in the detecting step, wherein the control step includes: A control signal is generated in the control signal generation step based on the carrier level detected in the detection step, the reference voltage generation step is controlled, and control is performed so that a carrier component contained in the spread modulation signal becomes a constant amount. The modulation control method according to claim 7, wherein 10. In the control step, when the carrier level detected in the detection step is larger than a predetermined amount, a control signal is generated in the control signal generation step, and a carrier component is transmitted from the reference voltage generation step to the modulator. A reference voltage is output so as to decrease, and if the carrier level detected in the detection step is smaller than a predetermined amount, a control signal is generated in the control signal generation step, and a carrier component is transmitted from the reference voltage generation step to the modulator. The modulation control method according to any one of claims 7 to 9, wherein control is performed to output a reference voltage so that the reference voltage is increased. 11. The modulation control method according to claim 7, wherein in the control step, control is performed to cut off a primary modulation signal at the start of transmission. 12. The modulation control method according to claim 7, wherein the modulation control method is applicable to spread spectrum communication using a quadrature phase modulation / demodulation method. 13. A storage medium readable by a computer storing a program for executing a modulation control method applied to a transmission / reception apparatus performing spread spectrum communication, wherein the modulation control method converts a spread modulation signal into a spread code. A despreading step of despreading a carrier component from the spread modulation signal based on the spread modulation signal; a detection step of detecting a carrier level; and a control step of controlling a carrier component contained in the spread modulation signal. Medium.