JPH08307287A - Radio communication equipment - Google Patents

Abstract

PURPOSE: To attain demodulation without degrading demodulation accuracy of a detector by changing an amplification factor of an amplifier in response to a power ratio of a signal with respect to noise even in the radio communication under a poor environment. CONSTITUTION: A received radio frequency signal is fed to an orthogonal demodulator 104 via a radio section 102 and an intermediate frequency amplifier 103, in which the signal frequency is converted into a base band frequency and at the same time separated into an in-phase component and a quadrature component. The in-phase component and the quadrature component are given respectively to transversal filters (TVF) 105a, 105b, in which the components are in correlation with a preamble pattern for S/N detection to improve the S/N. Then, the signal is given to an amplitude extract device 106, the amplitude component obtained by applying square averaging to outputs of the TVF 105a, 105b in a timing of an S/N detection bit is converted into a voltage level. Then, the signal is given to a comparator 107, in which the signal is compared with an external reference voltage. Its output is used to control a gain of the intermediate frequency amplifier 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device which automatically changes the amplification degree according to a received signal.

[0002]

2. Description of the Related Art The recent development of wireless communication devices is remarkable. Hereinafter, a conventional automatic gain control apparatus for a wireless communication device will be described with reference to the drawings.

FIG. 11 is a block diagram showing the configuration of a conventional automatic gain control device for a wireless communication device. Reference numeral 901 is an antenna for receiving a radio frequency signal, 902 is a radio section for extracting a modulation signal having an intermediate frequency from the radio frequency signal received by the antenna 901, and 903 is a modulation for outputting an input modulation signal by an external control signal. An intermediate frequency amplifier capable of adjusting the signal level, 904 is an envelope detector that performs envelope detection of the signal from the intermediate frequency amplifier 903, and 905 is an envelope detection output from the envelope detector 904 and a reference voltage. A comparator that performs comparison and controls from the intermediate frequency amplifier 903, and a detector 906 that reproduces data from the modulated signal from the intermediate frequency amplifier 903.

With this configuration, the modulated wave is generated by the intermediate frequency amplifier 90.
Amplified by 3 and sent to the envelope detector 904. The envelope detector 904 performs envelope detection of the amplified modulated wave and outputs the signal level of the modulated signal to the comparator 905. The comparator 905 compares the signal level of the modulation signal sent from the envelope detector 904 with the reference voltage,
When the signal level of the modulation signal is higher than the reference voltage, the gain of the intermediate frequency amplifier 903 is controlled to decrease, and when the signal level of the modulation signal is lower than the reference voltage, the gain of the intermediate frequency amplifier 901 is controlled to increase. Since the conventional automatic gain control device for a wireless communication device controls the intermediate frequency amplifier 903 so that the signal level of the modulation signal input to the comparator 905 approaches the reference voltage, the input signal power level of the detector 906 is kept constant. Can be kept.

[0005]

However, in the above-mentioned conventional configuration, since the magnitude of the output from the intermediate frequency amplifier is controlled to be constant, the noise level is large and the target signal level is small. In this case, there is a case where the size of the target signal is small and only noise is large, which causes deterioration of demodulation accuracy of the detector.

In view of the above problems, it is an object of the present invention to provide a wireless communication apparatus which does not reduce the demodulation accuracy of the detector even when the noise level is high or the target signal level is low. .

[0007]

In order to solve the above-mentioned conventional problems, the present invention changes the amplification degree of the amplifier according to the power ratio of the signal to noise of the signal output from the amplifier.

Further, control is performed so that the amplification degree is changed so that the power ratio of the signal to the noise is maximized.

Further, the quadrature demodulating means for separating the output from the amplifying portion into the in-phase component and the quadrature component and outputting the same, and the S / N ratio for correlating each output from the quadrature demodulating means with a predetermined signal pattern. The improvement means, the amplitude extractor for extracting the amplitude from the output from the S / N ratio improving means, and the control unit for changing the amplification degree of the amplifier according to the signal from the amplitude extractor are provided.

Further, this amplitude extractor adds the square of the absolute value of the output of the in-phase component from the S / N ratio improving means and the square of the absolute value of the output of the quadrature component from the S / N ratio improving means. The value obtained by taking the square root of what was done was output.

Further, this amplitude extractor compares the output ratios of the output of the in-phase component and the output of the quadrature component from the S / N ratio improving means, and gives the minimum value when the output ratio becomes maximum. The value obtained by adding 1/2 of the hour value is output.

Further, the control section is composed of an error signal extractor for extracting the variation of the output from the amplitude extraction section and changing the amplification degree of the amplifier based on the extracted result.

Further, the control section is composed of a comparator for outputting the result of comparing the output from the amplitude extractor and the reference value to the amplifier.

Further, the amplification section amplifies the modulation signal received by the time division multiplex communication, and the S / N ratio improving means sets the preamble pattern for frame synchronization of the time division multiplex communication to a predetermined signal pattern. And

Further, an amplifier capable of amplifying the spread spectrum signal and varying the amplification degree from the outside, a quadrature demodulating means for separating the output from the amplifying portion into an in-phase component and a quadrature component, and outputting the quadrature demodulating means. Despreading means for despreading each signal from each output from, the amplitude extractor for extracting the amplitude from the output from the despreading means, and the amplification degree of the amplifier is changed according to the signal from the amplitude extractor. And a control unit for controlling.

[0016]

With the above construction, the input S / N in the quadrature demodulation period can be made constant by controlling the gain of the intermediate frequency amplifier so that the amplified signal becomes constant.

The amplitude signal can be extracted by a comparator and an adder instead of the root mean square.

Further, the input S / N of the quadrature demodulator can be maximized by controlling the gain of the intermediate frequency amplifier so that the amplitude signal is maximized.

Furthermore, the input S / N in the orthogonal demodulation period can be maximized by using a frame synchronization detection preamble pattern instead of the S / N improving preamble pattern.

Further, it is possible to maximize the input S / N in the quadrature demodulation period by using a spread spectrum spread pattern instead of the frame detection preamble pattern.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention, FIG. 2 is a timing diagram showing the transmission / reception timing of the first embodiment of the present invention, and FIG. 3 is the first embodiment of the present invention. FIG. 4 is a block diagram showing the structure of a transversal filter, which is a data format showing the data structure in the embodiment.

In FIG. 1, 101 is an antenna for receiving radio frequency signals and 102 is an antenna 1 as constituent elements.
A radio unit for extracting a modulation signal having an intermediate frequency from the radio frequency signal received in 01, 103 is an intermediate frequency amplifier for adjusting the level of the modulation signal sent from the radio unit 102 by an external control signal, and outputting the adjusted signal. Reference numeral 104 denotes a quadrature demodulator that converts the modulation signal from the intermediate frequency amplifier 103 from the intermediate frequency to the baseband frequency and at the same time separates it into an in-phase component and a quadrature component, and 105a correlates with a preamble pattern for S / N detection to obtain an in-phase component. Transversal filter for improving the S / N of the
A transversal filter for improving the S / N of orthogonal components by correlating with a preamble pattern for detection, 106
Is an amplitude extractor that outputs a square-mean amplitude component of the output of the transversal filter 105a for the in-phase component and the output of the transversal filter 105b for the quadrature component as a voltage level signal at the timing of the preamble pattern for S / N detection. A comparator for comparing the voltage of the signal sent from the amplitude extractor with a reference voltage input from the outside to control the intermediate frequency amplifier 103, and 108 for frame processing of the quadrature demodulated modulated signal and at the same time reproducing data. It is a detector that does.

The TDD communication performed by the wireless communication device of the first embodiment will be described with reference to FIG. The wireless communication device 1 and the wireless communication device 2 use one interval (slot: an up slot and a down slot are synchronized by frame synchronization) that is temporally uniformly divided into the same frequency or a plurality of frequencies to transmit / receive data. Interact with. Here, the wireless communication device 1 and the wireless communication device 2 compress and transmit data such as one frame of voice data, and extend the received data of voice and the like in one slot into one frame for data exchange. There is. For example, the wireless communication device 1 transmits data in the transmission slot T1 and receives data in the reception slot R1. On the other hand, the wireless communication device 2 transmits data in the transmission slot T2 and receives data in the reception slot R2.

In FIG. 3, reference numeral 1 denotes a data format of a transmission slot at the time of transmission or a reception slot at the time of reception. A frame synchronization detection bit for inserting a preamble pattern for frame synchronization, and an S for inserting a preamble pattern for S / N detection. / N detection bit and a data area for storing data such as voice and image.

In FIG. 4, reference numeral 1051 denotes a delay line having the same delay amount as the S / N detection bit length of the data format 1,
Reference numeral 1052 denotes a weighter for multiplying the input data Si and the tap gain pattern Ri to perform weighting, using the same data pattern as the S / N detection bit of the data format 1 as a tap gain pattern, and 1053 denotes all weighters 1052.
It is an adder that adds the calculation results of. S / N detection bit
Of the M / S / N detection bit pattern and the phase of the tap gain pattern Ri match, and the S / N detection bit pattern
When the pattern is input, the output S of the adder is

[0027]

[Equation 1]

(The average value of the input Si is 1 and the input S / N =
γ), and let Aj be the average value of the output of the adder when white noise Nij (average is 1 / γ) is input instead of the S / N detection bit.

[0029]

[Equation 2]

It can be expressed as Therefore, S / N = Mγ
And the transversal filter 105
When S / N detection bit is input to a and 105b, S / N
Can be improved by 20 log (M).

The operation of the automatic gain control device for a wireless communication device configured as described above will be described in detail below with reference to FIGS. 1, 2 and 3.

The radio frequency signal received by the antenna 101 is extracted by the radio section 102 as a modulated signal having an intermediate frequency. The modulation signal is level-adjusted by the intermediate frequency amplifier 103 and sent to the quadrature demodulator 104, where it is converted from the intermediate frequency to the baseband frequency and at the same time separated into the in-phase component and the quadrature component. Since the in-phase component and the quadrature component can be correlated with the S / N detection preamble pattern by the transversal filters 105a and 105b, respectively,
The S / N is improved at the S / N detection bit position of the reception slot, and the noise level with respect to the signal level is reduced.
The amplitude extractor 106 uses the transversal filter 105 at the timing of the S / N detection bit of the data format 1.
The amplitude component obtained by the root mean square of the outputs of a and 105b is converted into a voltage level and output. Here, when the noise level with respect to the input signal level becomes sufficiently small due to the S / N improvement in the transversal filters 105a and 105b, it can be considered that the S / N is proportional to the amplitude component. Therefore, the comparator 107 sets the amplitude extractor 10 at the timing of the S / N detection bit of the data format 1.
Voltage level signal from 6 and arbitrary S input from outside
The reference voltage corresponding to / N is compared, and when the reference voltage is large, the gain of the intermediate frequency amplifier 103 is controlled to be increased, and when the reference voltage is small, the intermediate frequency amplifier 103 is controlled.
The gain is controlled to decrease.

In this way, the automatic gain control device for the wireless communication device of the first embodiment controls the gain of the intermediate frequency amplifier 103 so that the amplitude component corresponds to an arbitrary S / N, so S /
N can be kept constant.

A second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a block diagram showing the configuration of the second embodiment of the present invention, and FIG. 6 is a block diagram showing the configuration of the arithmetic circuit of the amplitude extractor.

In FIG. 5, as constituent elements 101 is an antenna for receiving a radio frequency signal, and 102 is an antenna 1.
A radio unit for extracting a modulation signal having an intermediate frequency from the radio frequency signal received in 01, 103 is an intermediate frequency amplifier for adjusting the level of the modulation signal sent from the radio unit 102 by an external control signal, and outputting the adjusted signal. Reference numeral 104 denotes a quadrature demodulator that converts the modulation signal from the intermediate frequency amplifier 103 from the intermediate frequency to the baseband frequency and at the same time separates it into an in-phase component and a quadrature component, and 105a correlates with a preamble pattern for S / N detection to obtain an in-phase component. Transversal filter for improving the S / N of the
A transversal filter for improving the S / N of orthogonal components by correlating with a preamble pattern for detection, 201
Is obtained by comparing the output of the transversal filter 105a for the in-phase component and the output of the transversal filter 105b for the quadrature component at the timing of the preamble pattern for S / N detection, and adding the half value and the maximum value. Amplitude extractor for outputting the amplitude component as a voltage level signal, 1
Reference numeral 07 is a comparator for comparing the voltage of the signal sent from the amplitude extractor with a reference voltage input from the outside to control the intermediate frequency amplifier, and 108 is for performing frame processing of the quadrature demodulated modulated signal and at the same time for data It is a detector that performs regeneration.

In FIG. 6, reference numeral 2011 is a comparator for comparing the input in-phase component and quadrature component, 2012 is a selector for selecting a signal according to a control signal from the comparator, and 2013 is a multiplication for halving the input signal. And 2014 is an adder that performs addition. The comparator 2011 compares the input in-phase component and quadrature component, and when the in-phase component is large, the selector selects the quadrature component so that the quadrature component is input to the multiplier 2013, and the in-phase component is input to the adder. The amplitude component is calculated by adding the in-phase component and the in-phase component. On the contrary, the comparator 2011 compares the input in-phase component and quadrature component, and when the quadrature component is large,
In-phase component is multiplier 2013, quadrature component is adder 2014
The selector selects so as to input to the input terminal, and the adder 2014 adds the half of the in-phase component and the quadrature component to calculate the amplitude component.

The operation of the automatic gain control device for a wireless communication device configured as described above will be described in detail below with reference to FIG. In the second embodiment, TDD communication is performed with the same data structure as in the first embodiment.

The radio frequency signal received by the antenna 101 is extracted by the radio section 102 as a modulated signal having an intermediate frequency. The modulation signal is level-adjusted by the intermediate frequency amplifier 103 and sent to the quadrature demodulator 104, where it is converted from the intermediate frequency to the baseband frequency and at the same time separated into the in-phase component and the quadrature component. Since the in-phase component and the quadrature component can be correlated with the S / N detection preamble pattern by the transversal filters 105a and 105b, respectively,
The S / N is improved at the S / N detection bit position of the reception slot, and the noise level with respect to the signal level is reduced.
The amplitude extractor 201 uses the transversal filter 105 at the timing of the S / N detection bit of data format 1.
The outputs of a and 105b are compared, and the amplitude component obtained by adding 1/2 of the minimum value and the maximum value is converted into a voltage level and output. Here, the transversal filter 105a,
When the noise level with respect to the input signal level becomes sufficiently small due to the S / N improvement in 105b, it can be considered that the S / N is proportional to the amplitude component. Therefore, the comparator 107 compares the voltage level signal from the amplitude extractor 201 with the reference voltage corresponding to an arbitrary S / N input from the outside at the timing of the S / N detection bit of the data format 1, and the reference voltage is large. In the case, the gain of the intermediate frequency amplifier 103 is controlled to be increased, and when the reference voltage is small, the gain of the intermediate frequency amplifier 103 is controlled to be decreased.

In this way, since the automatic gain control device for the wireless communication device of the second embodiment controls the gain of the intermediate frequency amplifier 103 so that the amplitude component corresponds to an arbitrary S / N, S /
N can be kept constant.

A third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a block diagram showing the configuration of the third exemplary embodiment of the present invention.

In FIG. 7, 101 is an antenna for receiving a radio frequency signal, and 102 is an antenna 1 as constituent elements.
A radio unit for extracting a modulation signal having an intermediate frequency from the radio frequency signal received in 01, 103 is an intermediate frequency amplifier for adjusting the level of the modulation signal sent from the radio unit 102 by an external control signal, and outputting the adjusted signal. Reference numeral 104 denotes a quadrature demodulator that converts the modulation signal from the intermediate frequency amplifier 103 from the intermediate frequency to the baseband frequency and at the same time separates it into an in-phase component and a quadrature component, and 105a correlates with a preamble pattern for S / N detection to obtain an in-phase component. Transversal filter for improving the S / N of the
A transversal filter for improving the S / N of orthogonal components by correlating with a preamble pattern for detection, 201
Is obtained by comparing the output of the transversal filter 105a for the in-phase component and the output of the transversal filter 105b for the quadrature component at the timing of the preamble pattern for S / N detection, and adding the half of the minimum value and the maximum value. And an error signal extractor 301 for extracting the amount of change of the amplitude signal and controlling the intermediate frequency amplifier 103, and 108 for performing frame processing of the quadrature-demodulated modulated signal and simultaneously It is a detector that performs regeneration.

The operation of the automatic gain control device for a wireless communication device configured as described above will be described in detail below with reference to FIG. In the third embodiment, TDD communication is performed with the same data structure as in the first embodiment.

The radio frequency signal received by the antenna 101 is extracted by the radio section 102 as a modulated signal having an intermediate frequency. The modulation signal is level-adjusted by the intermediate frequency amplifier 103 and sent to the quadrature demodulator 104, where it is converted from the intermediate frequency to the baseband frequency and at the same time separated into the in-phase component and the quadrature component. Since the in-phase component and the quadrature component can be correlated with the S / N detection preamble pattern by the transversal filters 105a and 105b, respectively,
The S / N is improved at the S / N detection bit position of the reception slot, and the noise level with respect to the signal level is reduced.
The amplitude extractor 201 uses the transversal filter 105 at the timing of the S / N detection bit of the data format 1.
The outputs of a and 105b are compared, and the half value of the minimum value and the maximum value are added and output as an amplitude signal. Here, when the noise level with respect to the input signal level becomes sufficiently small due to the S / N improvement in the transversal filters 105a and 105b, it can be considered that the S / N is proportional to the amplitude component. The polarity of the change is the polarity of the S / N change. Therefore, the error signal extractor 301 detects the amplitude signal S / N detection b of the data format 1 for each frame.
It is taken in the shift register at the timing of it and compared with the amplitude signal of two frames before. When the amplitude is increasing, the control direction of the intermediate frequency amplifier 103 is maintained, and when the amplitude is decreasing, the intermediate frequency amplifier is maintained. The control direction of 103 is reversed.

In this way, the automatic gain control apparatus for the wireless communication device of the third embodiment controls the gain of the intermediate frequency amplifier 103 in the direction in which the amplitude component increases, so that the S / N can be maximized.

A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a block diagram showing the configuration of the fourth embodiment of the present invention, and FIG. 9 is a data format showing the data configuration of the fourth embodiment of the present invention.

In FIG. 8, as constituent elements 101 is an antenna for receiving a radio frequency signal, and 102 is an antenna 1.
A radio unit for extracting a modulation signal having an intermediate frequency from the radio frequency signal received in 01, 103 is an intermediate frequency amplifier for adjusting the level of the modulation signal sent from the radio unit 102 by an external control signal, and outputting the adjusted signal. Reference numeral 104 denotes a quadrature demodulator that converts the modulation signal from the intermediate frequency amplifier 103 from the intermediate frequency to the baseband frequency and at the same time separates it into an in-phase component and a quadrature component, and 401a correlates with a preamble pattern for frame detection and S of the in-phase component is obtained. / N
The transversal filter 401b improves the S / N of the orthogonal component by correlating with the preamble pattern for frame detection, and 401b.
Reference numeral 02 is an amplitude signal obtained by comparing the output of the transversal filter for the in-phase component and the output of the transversal filter for the quadrature component at the timing of the preamble pattern for frame detection and adding the half value of the minimum value and the maximum value. , An error signal extractor 301 for extracting the amount of change in the amplitude signal and controlling the intermediate frequency amplifier 103,
Reference numeral 403 is a detector that performs frame processing of the modulated signal subjected to quadrature demodulation and at the same time reproduces data.

In FIG. 9, reference numeral 2 denotes a data format of a transmission slot at the time of transmission or a reception slot at the time of reception. From a data area for storing data such as a frame synchronization bit for inserting a preamble pattern for frame synchronization and data for voice or image. Composed.

The operation of the automatic gain control device for a wireless communication device configured as described above will be described in detail below with reference to FIG. The fourth embodiment has the first data structure shown in FIG.
The same TDD communication as in the above embodiment is performed.

The radio frequency signal received by the antenna 101 is extracted by the radio section 102 as a modulated signal having an intermediate frequency. The modulation signal is level-adjusted by the intermediate frequency amplifier 103 and sent to the quadrature demodulator 104, where it is converted from the intermediate frequency to the baseband frequency and at the same time separated into the in-phase component and the quadrature component. The in-phase component and the quadrature component are correlated with the preamble pattern for frame detection by the transversal filters 401a and 401b, respectively, so that the S / N at the position of the frame detection bit of the reception slot.
And the noise level with respect to the signal level is reduced. The amplitude extractor 402 compares the outputs of the transversal filters 401a and 401b at the timing of the data format 2 frame detection bit, adds half of the minimum value and the maximum value, and outputs the result as an amplitude signal. here,
S / in the transversal filters 401a and 401b
When the noise level with respect to the input signal level becomes sufficiently small due to the N improvement, it can be considered that the S / N is proportional to the amplitude component, and the polarity of the change of the amplitude signal is S / N.
It becomes the polarity of change. Therefore, the error signal extractor 301 takes the amplitude signal into the shift register for each frame at the timing of the frame detection bit of the data format 2 and compares the amplitude signal with the amplitude signal two frames before. Maintain the control direction of the frequency amplifier 103,
When the amplitude is decreasing, the control direction of the intermediate frequency amplifier 103 is reversed.

In this way, the automatic gain control apparatus for the wireless communication device of the fourth embodiment controls the gain of the intermediate frequency amplifier 103 in the direction in which the amplitude component increases, so that the S / N can be maximized.

A fifth embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a block diagram showing the configuration of the fifth exemplary embodiment of the present invention.

In FIG. 10, as constituent elements 101 is an antenna for receiving a radio frequency signal, 102 is a radio section for extracting a modulated signal of an intermediate frequency from the radio frequency signal received by the antenna 101, and 103 is a signal sent from the radio section 102. An intermediate frequency amplifier that adjusts the level of the received modulation signal by an external control signal and outputs the modulated signal. Reference numeral 104 converts the modulation signal from the intermediate frequency amplifier 103 from the intermediate frequency to the baseband frequency, and at the same time converts it into an in-phase component and an orthogonal component A quadrature demodulator for separating, 501a is a despreader for improving the S / N of the in-phase component by correlating with the spreading pattern on the transmitting side, and 501b is a despreader for correlating with the spreading pattern on the transmitting side to obtain the S / N of the orthogonal component. A despreader to be improved, 502 is an in-phase despreader 501a at a timing of once per frame.
Is compared with the output of the quadrature component despreader 501b, and an amplitude extractor that outputs an amplitude signal obtained by adding the half value of the minimum value and the maximum value is extracted, and 301 is a change amount of the amplitude signal. An error signal extractor for controlling the intermediate frequency amplifier 103, and a detector 503 for performing frame processing of the quadrature demodulated modulated signal and reproducing data at the same time.

The operation of the automatic gain control device for a wireless communication device configured as described above will be described in detail below with reference to FIG. In the fifth embodiment, it is assumed that the data structure shown in FIG. 9 is used to perform spread spectrum, and at the same time, the same TDD communication as in the first embodiment is performed.

The radio frequency signal received by the antenna 101 is extracted by the radio section 102 as a modulated signal having an intermediate frequency. The modulation signal is level-adjusted by the intermediate frequency amplifier 103 and sent to the quadrature demodulator 104, where it is converted from the intermediate frequency to the baseband frequency and at the same time separated into the in-phase component and the quadrature component. The in-phase component and the quadrature component are despreaders 501.
Since a and 501b are respectively correlated with the spreading pattern on the transmitting side, the S / N is improved in the entire receiving slot and the noise level with respect to the signal level is reduced. The amplitude extractor 502 de-spreads 501a, 5a at the timing of the first bit of the data area of the data format 2.
The outputs of 01b are compared, and half of the minimum value and the maximum value are added and output as an amplitude signal.

Here, if the noise level with respect to the input signal level becomes sufficiently small due to the S / N improvement in the despreaders 501a and 501b, it can be considered that the S / N is proportional to the amplitude component, The polarity of the change in the amplitude signal is S
It becomes the polarity of the change of / N. Therefore, the error signal extractor 30
1 takes the amplitude signal into the shift register every frame and compares it with the amplitude signal two frames before, and maintains the control direction of the intermediate frequency amplifier 103 when the amplitude increases,
When the amplitude is decreasing, the control direction of the intermediate frequency amplifier 103 is reversed.

In this way, the automatic gain control apparatus for the wireless communication device of the fifth embodiment controls the gain of the intermediate frequency amplifier 103 in the direction in which the amplitude component increases, so that the S / N can be maximized.

[0057]

As described above, according to the present invention, the amplification degree of the amplifier is changed according to the power ratio of the signal to the noise of the signal output from the amplifier. It becomes possible to perform reproduction, is less susceptible to noise, and can perform demodulation without degrading the demodulation accuracy of the detector.

Furthermore, since the control is performed so that the amplification degree is changed so that the power ratio of the signal to the noise is maximized, the demodulation accuracy of the detector can be maximized, and more accurate demodulation can be performed. It can be carried out.

Further, in the case of time division multiplex communication, the S / N ratio improving means sets the preamble pattern for frame synchronization of the time division multiplex communication as a predetermined signal pattern, so as to improve the S / N ratio. Since it is not necessary to prepare the signal pattern of, the circuit scale can be reduced, and the cost and size can be reduced.

Further, when demodulating the spread spectrum signal, by extracting the amplitude from the output from the despreading means, it becomes unnecessary to newly use the S / N improving means,
The circuit scale can be reduced, and the cost and size can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a timing chart showing transmission / reception timing of the first embodiment of the present invention.

FIG. 3 is a data format showing a data structure in the first embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a transversal filter.

FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an arithmetic circuit of an amplitude extractor.

FIG. 7 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 9 is a data format showing a data structure in the fourth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a fifth exemplary embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of a conventional automatic gain control device for a wireless communication device.

[Explanation of symbols]

 101 Antenna 102 Radio Section 103 Intermediate Frequency Amplifier 104 Quadrature Demodulator 105a, 105b Transversal Filter 106 Amplitude Extractor 107 Comparator 108 Detector

Claims (14)

[Claims] 1. An amplifier capable of amplifying an input modulation signal and varying the amplification degree from the outside, an extraction unit for extracting a power ratio of a signal to a noise of a signal output from the amplifier, and the extraction unit. And a control unit that changes the amplification degree of the amplifier according to the output from the wireless communication device. 2. The wireless communication device according to claim 1, wherein the control unit changes the amplification degree of the amplifier so that the output from the extraction unit is maximized. 3. The wireless communication device according to claim 1, wherein the control unit changes the amplification degree of the amplifier so that the output from the extraction unit becomes constant. 4. An amplifier capable of amplifying an input modulated signal and varying its amplification degree from the outside, and a quadrature demodulating means for separating an output from the amplifying section into an in-phase component and a quadrature component and outputting the same. An S / N ratio improving means for correlating each output from the quadrature demodulating means with a predetermined signal pattern, an amplitude extractor for extracting an amplitude from an output from the S / N ratio improving means, and the amplitude extracting And a control unit that changes the amplification degree of the amplifier according to a signal from the radio communication device. 5. The amplitude extractor divides the square of the absolute value of the output of the in-phase component from the S / N ratio improving means and the square of the absolute value of the output of the quadrature component from the S / N ratio improving means. The wireless communication device according to claim 4, wherein the value obtained by taking the square root of the sum of the additions is output. 6. The amplitude extractor compares the output ratios of the output of the in-phase component and the output of the quadrature component from the S / N ratio improving means, and minimizes the value when the output ratio becomes maximum. The wireless communication device according to claim 4, wherein a value obtained by adding a half of the value at the time of is output. 7. The control unit comprises an error signal extractor for extracting the amount of change in the output from the amplitude extracting unit and changing the amplification degree of the amplifier based on the extracted result. The wireless communication device according to any one of 4 to 6. 8. The wireless device according to claim 4, wherein the control unit is a comparator that outputs a result of comparison between an output from the amplitude extractor and a reference value to the amplifier. Communication device. 9. The amplifying unit amplifies the modulated signal received by time division multiplexing communication, and the S / N ratio improving means sets a preamble pattern for frame synchronization of the time division multiplexing communication. The wireless communication device according to any one of claims 4 to 8, wherein: 10. An amplifier capable of amplifying a spread spectrum signal and varying its amplification degree from the outside, a quadrature demodulating means for separating and outputting an output from the amplifying section into an in-phase component and a quadrature component, and the quadrature. Despreading means for despreading each signal from each output from the demodulation means,
A radio communication device comprising: an amplitude extractor for extracting an amplitude from an output from the despreading means; and a control unit for changing an amplification degree of the amplifier according to a signal from the amplitude extractor. 11. The amplitude extractor adds the square of the absolute value of the output of the in-phase component from the despreading means and the square of the absolute value of the output of the quadrature component from the S / N ratio improving means. 11. The wireless communication device according to claim 10, wherein a value obtained by taking a square root of the output is output. 12. The amplitude extractor compares the output ratios of the output of the in-phase component and the output of the quadrature component from the despreading means, and determines the value when the output ratio is the minimum value. The wireless communication device according to claim 10, wherein a value obtained by adding 1/2 of the value is output. 13. The control unit comprises an error signal extractor for extracting the amount of change in the output from the amplitude extracting unit and changing the amplification degree of the amplifier based on the extracted result. The wireless communication device according to any one of 10 to 12. 14. The radio according to claim 10, wherein the control unit is a comparator that outputs a result obtained by comparing an output from the amplitude extractor and a reference value to the amplifier. Communication device.