JPH08298483A - Diversity receiver - Google Patents

Abstract

PURPOSE: To attain accurate diversity control even in a radio channel including much noise in the diversity system in a radio communication equipment. CONSTITUTION: Plural antennas 1 are used to receive the same signal, each RF/IF module 2 converts the frequency and conducts orthogonal demodulation to separate the signal into biphase orthogonal signals. A transversal filter 7 generates the biphase orthogonal signals whose S/N is improved from the biphase orthogonal signals above and they are multiplied with detection outputs of the biphase signals being outputs of orthogonal demodulation as a weight coefficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of antennas, selects or combines a radio signal having a good communication quality among radio signals received from the antennas, and selects or combines the radio signals. The present invention relates to a diversity receiver that performs reproduction.

[0002]

2. Description of the Related Art As a diversity system in a conventional wireless communication apparatus, there is a system shown in "Digitalization technology of mobile communication", Trikeps (1990), and its configuration is shown in FIG. In the figure, 1 is an antenna, 2 is RF / IF
Module, 8 is a detector, 23 is an envelope detector, 18 is a comparator, 17 is a selector, and 14 is reproduction data.

The operation of the conventional diversity system configured as described above will be described below.

In a fading transmission line, a plurality of signals arriving via different transmission lines are multiplexed and received by a plurality of antennas 1. After the received signal goes through the antenna 1,
IF in the corresponding RF / IF module 2
Alternatively, the frequency is converted to the baseband band. RF /
The envelope level of each of the signals output from the IF module 2 is extracted in the envelope detector 23, and the envelope levels output from the respective envelope detectors 23 are compared in the comparator 18. On the other hand, multiple RF /
The signal output from the IF module 2 is demodulated in the detector 8. Then, in the selector 17,
Based on the output of the comparator 18, the output of the detector 8 corresponding to the signal having the highest envelope level is selected and output as reproduction data.

In this case, even if the signal level received by one antenna 1 is very small and there are many errors in the output of the detector 8, if the signal level received by another antenna 1 is within the allowable range, The output of the detector 8 is selected as the reproduction data. Therefore, the communication quality can be improved and the diversity effect can be obtained as compared with the wireless communication apparatus that does not perform diversity and is configured by only one antenna 1.

[0006]

However, in the above-mentioned conventional configuration, since the reception intensities from the respective antennas are compared, when the noise level is large or the target signal level is small, the influence of the noise level is affected. However, it has become impossible to accurately switch to the larger target radio signal.

According to the present invention, even if the noise level is high or the target signal level is low, the signal having the highest required signal level is extracted from the received signals received from the plurality of antennas, and the accurate signal is extracted. It is an object of the present invention to provide a diversity receiver capable of reproducing data.

[0008]

In order to solve the above-mentioned conventional problems, the present invention provides a detector for detecting a received radio signal and a signal power ratio (SN) to noise of a signal input to the detector. A reception modulator having an extraction unit for extracting the ratio) and an arithmetic unit for weighting the output of the detector with the output from the extraction unit is connected for each antenna, and the outputs of the respective reception modulators are used to transmit diversity. Take control.

Further, an orthogonal demodulation section for generating a two-phase signal from a radio signal by the orthogonal demodulation and two signals generated by the orthogonal demodulation section.
Output from the digital filter, a detector that detects the phase signal, a digital filter that filters the two-phase signal generated by the quadrature demodulation unit with a predetermined tap gain, and that improves the signal-to-noise ratio above a predetermined level. Connected to each antenna is a reception modulator having an extraction unit that extracts the amplitude from the two-phase output and a computing unit that weights the output of the detector with the output from the extraction unit, and the output of each reception modulator Is used to perform diversity control.

Further, in the case of time division two-way communication (TDD), a quadrature demodulation section for generating a two-phase signal from a radio signal by quadrature demodulation and a detector for detecting the two-phase signal generated by the quadrature demodulation section. And a digital filter that filters the two-phase signals generated by the quadrature demodulation unit using the preamble pattern of the time-division bidirectional communication frame as a tap gain, and an extraction that extracts the amplitude from the two-phase output output from the digital filter. A reception filter having a section and an arithmetic unit that weights the output of the detector with the output from the extraction section is connected to each antenna, and diversity control is performed using the output of each reception modulator.

Further, in the case of spread spectrum communication, a quadrature demodulation section for generating a two-phase signal from a radio signal by quadrature demodulation, a despreading section for despreading the two-phase signal generated by the quadrature demodulation section, and an inverse Reception having a detection unit that performs detection from the signal from the spreading unit, an extraction unit that extracts the amplitude of the output output from the despreading unit, and an arithmetic unit that weights the output of the detector with the output from the extraction unit A filter is connected to each antenna and diversity control is performed using the output of each reception modulator.

Further, the diversity control by the control unit is maximum ratio combining diversity control which is carried out by combining the weighted signals.

Alternatively, the diversity control by the control unit is a selective combining diversity control for selecting the signal having the largest signal among the weighted signals.

Further, the extraction unit sets the output values of the two phases output from the transversal filter or the despreading unit to the maximum value of each signal and 1/2 of the minimum value of each signal.
The amplitude is extracted by adding the values of.

[0015]

According to the present invention, since the diversity control is performed in consideration of the SN ratio by the above-described structure, the data of the target signal can be reproduced without being affected by the noise level even if the noise level is large. it can.

Further, the absolute value of the output from each transversal filter is added to the maximum value of each signal by 1/2 of the minimum value of each signal, and this value is used to extract the SN ratio of the amplitude. By treating as, it is possible to simplify the conversion from the vector quantity to the scalar quantity.

[0017]

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

(Embodiment 1) FIG. 1 is a block diagram showing Embodiment 1 of the diversity system of the present invention. In FIG. 1, 1
Is an antenna, 2 is an RF / IF module, 3 is a quadrature demodulator, 4 is a module A, 5 is a module B, 6 is a module C, 7 is a transversal filter, 8 is a detector,
Reference numeral 9 is an amplitude extractor, 10 is a data pattern extraction unit, 11 is a multiplier, 12 is an adder, 13 is a data determination unit, and 14 is reproduction data.

Next, the operation of the first embodiment of the diversity system of the present invention will be described with reference to FIG.

On the transmitting side, a data pattern known to the receiving side is inserted in the transmission signal in advance and transmitted. Then, in the fading transmission path, fading waves are received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected is performed by the module A
4, except for the operations of the module B5 and the module C6, only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4 and the transversal filter 7. The transversal filter 7 is configured as shown in the block diagram of FIG. 9, and the data pattern previously inserted in the transmission signal, for example, the same pattern as “1 ... Signals on the delay line 19 having the same length are weighted, and the results are added together by the adder 12 and output. From the outputs I and Q (not shown) of the two transversal filters 7,
In the amplitude extractor 9, the amplitude √ (I × I + Q × Q) of I and Q is calculated by using, for example, ROM or DSP.
On the other hand, the quadrature two-phase signal input to the module A4 is demodulated by the detector 8 (note that this detector 8 is shown in FIG.
A differential detection type detector as shown in FIG. 4), and the data pattern extraction unit 10 including a correlator causes the above-mentioned data pattern “1 ...
When 011 ″ is extracted, from the timing information, in the amplitude extractor 9, I when the data pattern of the tap gain in the transversal filter 7 and the data pattern on the corresponding delay line 19 in the multiplier 11 match.
Only the amplitude √ (I × I + Q × Q) of Q and Q is held and used as the output of the amplitude extractor 9. Then, every time the above-mentioned data pattern "1 ... 011" is extracted from the output of the detector 8, the output is updated. Further, the output of the detector 8 is multiplied by the amplitudes of I and Q when the phases of the above-mentioned data patterns match, that is, the output of the amplitude extractor 9, and becomes the output of the module A4.

In this case, assuming that the data pattern length is N, the SN ratio of the output of the amplitude extractor 9 is improved to N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and close to 1, the amplitudes of I and Q when the phases of the above-mentioned data patterns do not match (√ (I × I +
Q × Q) is not a quantity proportional to the SN ratio because the noise component is dominant, but if the data pattern length N is sufficiently large, the amplitudes of I and Q when the phases of the data patterns match, that is, the amplitude extractor 9 Is an amount proportional to the SN ratio of the received signal.

The difference between the operations of the module A4 and the modules B5 and C6 is that the timing information of the above-mentioned data pattern "1 ... 011" of the output of the detector 8 is generated from the data pattern extraction unit 10 of the module A4. Are shared by the modules B5 and C6, and based on the timing, the modules B5 and C6
Amplitude extractor 9 of I and Q amplitude √ (I × I + Q ×
Q) is output, and other configurations and operations are the same for all modules.

From each module, at the timing when the phase of the above-mentioned data pattern generated by the module A4 matches the detector 8 output of each module,
A signal weighted by the amplitudes of I and Q is output, and they are combined by the adder 12. Then, the data determination unit 13
The polarity of the combined amount is determined in
Is output as

In this case, even if the SN ratio of the received signal is small and close to 1, the combined amount of the outputs of the adder 12 is an amount equivalent to the amount of each fading wave weighted by the SN ratio for the above reason. become. That is, the SN ratio of the input of the data determination unit 13 is
It will be improved rather than the SN ratio for only one wave. Then, the communication quality is the input S of the data determination unit 13.
Considering that it is determined by the N ratio, even if the SN ratio of the received signal is small and close to 1, it is improved by the presence of the fading wave.

(Embodiment 2) FIG. 2 is a block diagram showing Embodiment 2 of the diversity system of the present invention. The main difference from the first embodiment is that the operation of inserting a known data pattern in the transmission signal in advance in the receiving side is not particularly performed, and TDD is adopted as the transmission method, so that the receiving side receives TDD.
The preamble pattern of the frame is handled in the same manner as the data pattern of the first embodiment.

In FIG. 2, 1 is an antenna and 2 is RF /
IF module, 3 is a quadrature demodulator, 4 is a module A,
5 is a module B, 6 is a module C, 7 is a transversal filter, 8 is a detector, 9 is an amplitude extractor, 15 is a TDD preamble pattern extraction unit, 11 is a multiplier, 1
Reference numeral 2 is an adder, 13 is a data determination unit, and 14 is reproduction data.

Next, the operation of the second embodiment of the diversity system of the present invention will be described with reference to FIG.

In the present invention, by adopting TDD as the transmission method, the TDD of the transmission signal is transmitted on the transmission side.
A known preamble pattern is inserted in the frame on the receiving side for synchronization and transmitted. Then, in the fading transmission path, the fading wave is received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected respectively, except for the operations of the module A4, the module B5, and the module C6. All the same so
Only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4, which is input to the transversal filter 7. The transversal filter 7 is configured as shown in the block diagram of FIG. 9, and uses a preamble pattern of the TDD frame, for example, the same pattern as “1 ... 110” as a tap gain, and a delay having the same length as the preamble pattern length. The signals on the line 19 are weighted, and the results are added together by the adder 12 and output. The outputs I and Q of the two transversal filters 7 (not shown)
Therefore, in the amplitude extractor 9, for example, a ROM or DSP
And the like are used to calculate the amplitude √ (I × I + Q × Q) of I and Q. On the other hand, the quadrature two-phase signal input to the module A4 is demodulated by the differential detection type detector 8 and, for example, the TDD preamble pattern extraction unit 1 configured by a correlator.
5, when the above-mentioned preamble pattern "1 ... 110" is extracted from the output of the detector 8, from the timing information, in the amplitude extractor 9, the tap gain preamble pattern in the transversal filter 7 shown in FIG. And the amplitude of I and Q when the preamble pattern on the corresponding delay line 19 in the multiplier 11 matches (√ (I
XI + QxQ) is held and used as the output of the amplitude extractor 9. Then, every time the above-mentioned preamble pattern "1 ... 110" is extracted from the output of the detector 8, the output is updated. Further, the output of the detector 8 is multiplied by the amplitudes of I and Q when the phases of the above preamble patterns match, that is, the output of the amplitude extractor 9 and becomes the output of the module A4.

In this case, assuming that the above-mentioned preamble pattern length is N, the SN ratio of the output of the amplitude extractor 9 is improved to N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and close to 1, the noise component is dominant in the amplitude √ (I × I + Q × Q) of I and Q when the phases of the above preamble patterns do not match.
Although the amount is not proportional to the N ratio, if the preamble pattern length N is sufficiently large, the amplitudes of I and Q when the phases of the preamble patterns match, that is, the output level of the amplitude extractor 9 is proportional to the SN ratio of the received signal. It becomes the amount.

The difference between the operations of the module A4 and the modules B5 and C6 is that the timing information of the above-mentioned preamble pattern "1 ... 110" of the output of the detector 8 generated from the preamble pattern extraction unit 15 of the module A4. Is shared by the modules B5 and C6, and based on the timing, the amplitudes I and Q of the amplitude extractors 9 of the modules B5 and C6 are √.
The output is (I × I + Q × Q), and other configurations and operations are the same for all modules.

From each module, the signal weighted by the I and Q amplitudes is generated at the timing when the phase of the above-mentioned preamble pattern is generated by the module A4 with respect to the output of the detector 8 of each module. Is output,
They are combined by the adder 12. Then, the data determination unit 13 determines the polarity of the combined amount and outputs it as the reproduction data 14.

In this case, even if the SN ratio of the received signal is small and close to 1, for the above reason, the combined amount of the outputs of the adder 12 is an amount equivalent to the amount of each fading wave weighted by the SN ratio. become. That is, the SN ratio of the input of the data determination unit 13 is
It will be improved rather than the SN ratio for only one wave. Then, the communication quality is the input S of the data determination unit 13.
Considering that it is determined by the N ratio, even if the SN ratio of the received signal is small and close to 1, it is improved by the presence of the fading wave.

(Embodiment 3) FIG. 3 is a block diagram showing Embodiment 3 of the diversity system of the present invention. The main difference from the first and second embodiments is that by using a spread spectrum communication method that spreads the spectrum by a direct spread method with a pseudo noise signal, the despreading unit 16 used in the demodulation process This is a means for improving the SN ratio of the extraction unit input signal.

In FIG. 3, 1 is an antenna and 2 is RF /
IF module, 3 is a quadrature demodulator, 4 is a module A,
5 is a module B, 6 is a module C, 8 is a detector, 9
Is an amplitude extractor, 11 is a multiplier, 12 is an adder, 13 is a data determination unit, and 14 is reproduction data.

Next, the operation of the third embodiment of the diversity system of the present invention will be described with reference to FIG.

In the present invention, the spread spectrum communication system is adopted, and the spectrum of the original information signal is spread by the pseudo noise signal and transmitted. Then, in the fading transmission path, the fading wave is received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected respectively, except for the operations of the module A4, the module B5, and the module C6. All the same so
Only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4, which is input to the despreading unit 16. The despreading unit 16 (configured as shown in the block diagram of FIG. 11) has the same pseudo noise signal generated by the pseudo noise generator 20 as the pseudo noise signal used for spread spectrum on the transmitting side. The noise signal is multiplied and the result is integrated by the integrator 21 for each 1-bit data. As a result, the spectrum spread in the wide band is returned to the narrow band, and the SN ratio is improved. Then, from the outputs I and Q (not shown) of the two despreading units 16, in the amplitude extractor 9, for example, a ROM
I / Q amplitude √ (I × I + Q × Q)
Is calculated. On the one hand, the outputs I and Q of the despreader 16
Is demodulated by the delay detection type detector 8, and in the amplitude extractor 9, the I and Q values when the received signal and the pseudo noise signal output from the pseudo noise generator 20 in the despreading unit 16 are in phase with each other. Only the amplitude √ (I × I + Q × Q) is held and used as the output of the amplitude extractor 9. Further, the output of the detector 8 is multiplied by the amplitudes of I and Q when the phases of the pseudo noise signals described above match, that is, the output of the amplitude extractor 9, and becomes the output of the module A4.

In this case, assuming that the pseudo noise signal length is N, the SN ratio of the output of the amplitude extractor 9 is improved N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and close to 1, the amplitudes of I and Q when the phases of the pseudo noise signals do not match (√ (I × I + Q ×
The noise component is dominant in Q) and is not proportional to the SN ratio, but if the pseudo noise signal length N is sufficiently large, the amplitudes of I and Q when the phases of the pseudo noise signals match, that is, the amplitude extractor 9 Is an amount proportional to the SN ratio of the received signal.

The difference between the operations of the module A4 and the modules B5 and C6 is that the output timing information of the amplitude extractor 9 generated in the module A4 corresponds to the module B.
5, shared by module C6, and based on the timing, the amplitude extractor 9 of module B5 and module C6
Is to output the amplitude √ (I × I + Q × Q) of I and Q, and other configurations and operations are the same for all modules.

From each module, at the timing when the phase of the above-mentioned pseudo noise signal generated by the module A4 matches the output of the detector 8 of each module, I
Signals weighted by the amplitudes of Q and Q are output, and they are combined by the adder 12. Then, the data determination unit 13 determines the polarity of the combined amount and outputs it as the reproduction data 14.

In this case, even if the SN ratio of the received signal is small and close to 1, the combined amount of the outputs of the adder 12 is an amount equivalent to the amount of each fading wave weighted by the SN ratio for the reason described above. become. That is, the SN ratio of the input of the data determination unit 13 is
It will be improved rather than the SN ratio for only one wave. Then, the communication quality is the input S of the data determination unit 13.
Considering that it is determined by the N ratio, even if the SN ratio of the received signal is small and close to 1, it is improved by the presence of the fading wave.

(Embodiment 4) FIG. 4 is a block diagram showing Embodiment 4 of the diversity system of the present invention. In FIG. 4, 1
Is an antenna, 2 is an RF / IF module, 3 is a quadrature demodulator, 4 is a module A, 5 is a module B, 6 is a module C, 7 is a transversal filter, 8 is a detector,
Reference numeral 9 is an amplitude extractor, 10 is a data pattern extraction unit, 17 is a selector, 18 is a comparator, and 14 is reproduction data.

The operation of the fourth embodiment of the diversity system of the present invention will be described with reference to FIG.

On the transmitting side, a data pattern known to the receiving side is inserted in the transmission signal in advance and transmitted. Then, in the fading transmission path, fading waves are received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected is performed by the module A
4, except for the operations of the module B5 and the module C6, only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4, which is input to the transversal filter 7. The transversal filter 7 has the configuration shown in the block diagram of FIG. 9, and has a data pattern inserted in the transmission signal in advance, for example, “1 ... 01”.
A signal on the delay line 19 having the same length as the data pattern length is weighted by using the same pattern as "1" as a tap gain, and the results are added together by the adder 12 and output. The two transversal filters 7 In the amplitude extractor 9, the amplitudes √ (I × I + Q × Q) of I and Q are calculated from the outputs I and Q (not shown) of I.Q. The quadrature two-phase signal thus obtained is demodulated by the differential detection type detector 8, and the data pattern extraction unit 10 constituted by, for example, a correlator outputs the above-mentioned data pattern "1 ...
When 011 ″ is extracted, the data pattern of the tap gain in the transversal filter 7 shown in FIG. 9 matches the data pattern on the corresponding delay line 19 in the multiplier 11 in the amplitude extractor 9 from the timing information. Only the amplitudes √ (I × I + Q × Q) of I and Q at time are held and used as the output of the amplitude extractor 9. Then, every time the above-mentioned data pattern “1 ... 011” is extracted from the output of the detector 8. To update its output.

In this case, assuming that the data pattern length is N, the SN ratio of the output of the amplitude extractor 9 is improved to N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and close to 1, the amplitudes of I and Q when the phases of the above-mentioned data patterns do not match (√ (I × I +
Q × Q) is not a quantity proportional to the SN ratio because the noise component is dominant, but if the data pattern length N is sufficiently large, the amplitudes of I and Q when the phases of the data patterns match, that is, the amplitude extractor 9 Is an amount proportional to the SN ratio of the received signal.

The difference between the operations of the module A4 and the modules B5 and C6 is that the timing information of the above-mentioned data pattern "1 ... 011" of the output of the detector 8 is generated from the data pattern extraction unit 10 of the module A4. Are shared by the modules B5 and C6, and based on the timing, the modules B5 and C6
Amplitude extractor 9 of I and Q amplitude √ (I × I + Q ×
Q) is output, and other configurations and operations are the same for all modules.

The amplitude level of each fading wave output from each module is compared in the comparator 18, and the output of the detector 8 of the received signal from the antenna 1 having the maximum amplitude level is selected as the reproduction data 14.

In this case, even if the SN ratio of the received signal is small and is close to 1, the reproduced data 14 is the detection output having the largest SN ratio among the fading waves for the above reason. That is, considering that the communication quality is determined by the SN ratio at the time of data determination, the SN of the received signal is
Even if the ratio is small and close to 1, the detection output of the fading wave with the best communication quality can be selected as the reproduction data 14.

(Embodiment 5) FIG. 5 is a block diagram showing Embodiment 5 of the diversity system of the present invention. The main difference from the above-described fourth embodiment is that the operation of inserting a known data pattern in advance in the transmission side in the transmission signal is not particularly performed and TDD is adopted as the transmission method, so that the reception side can perform TDD.
The preamble pattern of the frame is handled in the same manner as the data pattern of the fifth embodiment.

In FIG. 5, 1 is an antenna and 2 is RF /
IF module, 3 is a quadrature demodulator, 4 is a module A,
5 is a module B, 6 is a module C, 7 is a transversal filter, 8 is a detector, 9 is an amplitude extractor, 15 is a TDD preamble pattern extraction unit, 17 is a selector,
Reference numeral 18 is a comparator, and 14 is reproduction data.

The operation of the fifth embodiment of the diversity system of the present invention will be described with reference to FIG.

In the present invention, by adopting TDD as the transmission system, the TDD of the transmission signal is transmitted on the transmission side.
A known preamble pattern is inserted in the frame on the receiving side for synchronization and transmitted. Then, in the fading transmission path, the fading wave is received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected respectively, except for the operations of the module A4, the module B5, and the module C6. All the same so
Only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4, which is input to the transversal filter 7 shown in FIG. In the transversal filter 7, the preamble pattern of the TDD frame, for example, the same pattern as "1 ... 110" is used as the tap gain, and the delay line 19 having the same length as the preamble pattern length is used.
The upper signal is weighted, the result is compared by the comparator 18, and the selector 17 outputs the maximum of the comparison results. And the outputs I of the two transversal filters 7
And Q (not shown), the amplitude extractor 9 uses, for example, a ROM, a DSP, or the like, the amplitudes of I and Q √ (I × I +
Q × Q) is calculated. On the other hand, the quadrature two-phase signal input to the module A4 is demodulated by the differential detection type detector 8, and for example, the TDD preamble pattern extraction unit 15 constituted by a correlator outputs the above-mentioned preamble pattern from the detector 8 If you extract 1 ... 110 ”,
From the timing information, in the amplitude extractor 9, the I and Q amplitudes √ when the preamble pattern of the tap gain in the transversal filter 7 and the preamble pattern on the corresponding delay line 19 in the multiplier 11 match each other.
Only (I × I + Q × Q) is held and used as the output of the amplitude extractor 9. Then, every time the above-mentioned preamble pattern "1 ... 110" is extracted from the output of the detector 8, the output is updated.

In this case, assuming that the above-mentioned preamble pattern length is N, the SN ratio of the output of the amplitude extractor 9 is improved to N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and close to 1, the noise component is dominant in the amplitude √ (I × I + Q × Q) of I and Q when the phases of the above preamble patterns do not match.
Although the amount is not proportional to the N ratio, if the preamble pattern length N is sufficiently large, the amplitudes of I and Q when the phases of the preamble patterns match, that is, the output level of the amplitude extractor 9 is proportional to the SN ratio of the received signal. It becomes the amount.

The difference between the operations of the module A4 and the modules B5 and C6 is that the timing information of the above-mentioned preamble pattern "1 ... 110" of the detector 8 output, which is generated from the preamble pattern extraction unit 15 of the module A4. Is shared by the modules B5 and C6, and based on the timing, the amplitudes I and Q of the amplitude extractors 9 of the modules B5 and C6 are √.
The output is (I × I + Q × Q), and other configurations and operations are the same for all modules.

The amplitude level of each fading wave output from each module is compared in the comparator 18, and the output of the detector 8 from the antenna 1 having the maximum amplitude level is selected as the reproduction data 14.

In this case, even if the SN ratio of the received signal is small and is close to 1, the reproduced data 14 is a detection output having the largest SN ratio among the fading waves for the above reason. That is, considering that the communication quality is determined by the SN ratio at the time of data determination, the SN of the received signal is
Even if the ratio is small and close to 1, the detection output of the fading wave with the best communication quality can be selected as the reproduction data.

(Sixth Embodiment) FIG. 6 is a block diagram showing a sixth embodiment of the diversity system of the present invention. The main difference from the above-described fourth and fifth embodiments is that by using a spread spectrum communication method that spreads the spectrum by a direct spread method with a pseudo noise signal, the despreading unit 16 used in the demodulation process is This is a means for improving the SN ratio of the extraction unit input signal.

In FIG. 6, 1 is an antenna and 2 is RF /
IF module, 3 is a quadrature demodulator, 4 is a module A,
5 is a module B, 6 is a module C, 8 is a detector, 9
Is an amplitude extractor, 17 is a selector, 18 is a comparator, and 14 is reproduction data.

Next, the operation of the sixth embodiment of the diversity system of the present invention will be described with reference to FIG.

In the present invention, the spread spectrum communication system is adopted, and the spectrum of the original information signal is spread by the pseudo noise signal and transmitted. Then, in the fading transmission path, the fading wave is received by the plurality of antennas 1. However, the processing until the signals received by the respective antennas 1 are detected respectively, except for the operations of the module A4, the module B5, and the module C6. All the same so
Only one system will be described.

The received signal passes through the antenna 1 and then the RF / I
In the F module 2, the frequency is converted to the IF band.
The IF signal output from the RF / IF module 2 is input to the quadrature demodulation unit 3, and orthogonal two-phase baseband signals are generated. The generated quadrature two-phase signal is input to the module A4, which is input to the despreading unit 16. The despreading unit 16 has a configuration as shown in FIG. 11, and a pseudo noise signal generated by the pseudo noise generator 20 that is the same as the pseudo noise signal used for spreading the spectrum on the transmission side is generated. It is multiplied and the result is integrated by the integrator 21 for each 1-bit data. As a result, the spectrum spread in the wide band is returned to the narrow band, and the SN ratio is improved. Then, from the outputs I and Q (not shown) of the two despreading units 16, the amplitude extractor 9 calculates the amplitude √ (I × I + Q × Q) of I and Q by using, for example, a ROM or a DSP. It On the other hand, the outputs I and Q of the despreading unit 16 are demodulated by the delay detection type detector 8, and in the amplitude extractor 9, the despreading unit 16 outputs the received signal and the pseudo noise of the output of the pseudo noise generator 20. I and Q amplitudes when the signal phases match √
Only (I × I + Q × Q) is held and used as the output of the amplitude extractor 9.

In this case, assuming that the pseudo noise signal length is N, the SN ratio of the output of the amplitude extractor 9 is improved to N times the SN ratio of the input of the amplitude extractor 9. Therefore, when the SN ratio of the received signal is small and is close to 1, the amplitudes of I and Q when the phases of the pseudo noise signals do not match (√ (I × I + Q ×
Q) is not a quantity proportional to the SN ratio because the noise component is dominant, but if the pseudo noise signal length N is sufficiently large, the amplitudes of I and Q when the phases of the pseudo noise signals match, that is, the amplitude extractor 9 Is an amount proportional to the SN ratio of the received signal.

The difference between the operations of the module A4 and the modules B5 and C6 is that the output timing information of the amplitude extractor 9 generated by the module A4 is the same as that of the module B.
5, shared by module C6, and based on the timing, the amplitude extractor 9 of module B5 and module C6
Is to output the amplitude √ (I × I + Q × Q) of I and Q, and other configurations and operations are the same for all modules.

The amplitude levels of the fading waves output from the modules are compared by the comparator 18, and the output of the detector 8 from the antenna 1 having the maximum amplitude level is selected as the reproduction data 14.

In this case, even if the SN ratio of the received signal is small and close to 1, the reproduced data 14 is a detection output having the largest SN ratio among the fading waves for the above reason. That is, considering that the communication quality is determined by the SN ratio at the time of data determination, the SN of the received signal is
Even if the ratio is small and close to 1, the detection output of the fading wave with the best communication quality can be selected as the reproduction data 14.

(Embodiment 7) The above-mentioned embodiment 1, embodiment 2,
In the third embodiment, the fourth embodiment, the fifth embodiment, and the sixth embodiment, in the amplitude extractor 9, the amplitude amount of the quadrature two-phase signals I and Q of the input signal is √ (I × I + Q × Q). However, in the seventh embodiment, √ (I × I + Q ×
MAX (I, Q) + 0.5 × MIN which is an approximate solution of Q)
The configuration is such that (I, Q) is calculated as the amplitude amount. Here, MAX (I, Q) is the value of the higher level of I and Q, and MIN (I, Q) is the value of the lower level of I and Q. FIG. 7 and FIG. 8 show configuration examples of the amplitude amount calculation section in the diversity type amplitude extractor 9 of the seventh embodiment. 7 and 8, 18 is a comparator, 17
Is a selector.

In the present embodiment, for example, the part for multiplying by ½ can be realized by deleting the least significant bit of the signal and shifting the other bits to the lower bit by 1 bit, and the other part. Also, since it can be easily realized with a small number of gates, there is an advantage that the device scale can be reduced.

[0072]

The present invention provides a detector for detecting a received radio signal, an extraction unit for extracting a signal power ratio (SN ratio) to noise of a signal input to the detector, and an output of the detector. A reception modulator having a computing unit that performs weighting based on the output from the extraction unit is connected to each antenna, and diversity control is performed using the outputs of the respective reception modulators, so the objective is not affected by the SN ratio. The data reproduction can be performed, and the diversity control can be accurately performed even if the noise increases.

Also, the absolute value of the output from each transversal filter is added to the maximum value of each signal by 1/2 the minimum value of each signal, and this value is used as the extracted SN ratio. By treating as, it is possible to simplify the conversion from the vector quantity to the scalar quantity, and it is possible to reduce the size and weight of the reception modulator.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing a second embodiment of the diversity system of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the diversity system of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the diversity system of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the diversity system of the present invention.

FIG. 6 is a configuration diagram showing a sixth embodiment of the diversity system of the present invention.

FIG. 7 is a configuration diagram showing an example of implementation of an amplitude amount calculation unit in an amplitude extraction unit according to a seventh embodiment of the diversity system of the present invention.

FIG. 8 is a configuration diagram showing another example of implementation of the amplitude amount calculation unit in the amplitude extraction unit of the embodiment 7 of the diversity system of the present invention.

FIG. 9 is a configuration diagram of a transversal filter unit according to first and fourth embodiments of the present invention.

FIG. 10 is a configuration diagram of a transversal filter unit according to second and fifth embodiments of the present invention.

FIG. 11 is a configuration diagram of a despreading unit according to third and sixth embodiments of the present invention.

FIG. 12 is a configuration diagram of wave detectors according to the first, second, third, fourth, fifth and sixth embodiments of the present invention.

FIG. 13 is a block diagram of a conventional diversity system.

[Explanation of symbols]

 1 Antenna 2 RF / IF Module 3 Quadrature Demodulator 4 Module A 5 Module B 6 Module C 7 Transversal Filter 8 Detector 9 Amplitude Extractor 10 Data Pattern Extractor 11 Multiplier 12 Adder 13 Data Determinator 14 Playback Data 15 TDD preamble pattern extraction unit 16 despreading unit 17 selector 18 comparator 19 delay line 20 pseudo noise generator 21 integrator 22 delay element 23 envelope detector

Claims (7)

[Claims] 1. A plurality of antennas, a plurality of receiving modules provided in each of the plurality of antennas for receiving the same frequency, and a control section for performing diversity control by outputs from the plurality of receiving modules. The plurality of receiving modules respectively include a detector that detects a signal of a frequency, an extraction unit that extracts a power ratio of a signal to a noise of a signal input to the detector, and the output of the detector. And a computing unit that performs weighting according to the output from the unit. 2. A plurality of antennas, a plurality of receiving modules provided in each of the plurality of antennas for receiving the same signal respectively, and a control section for performing diversity control based on signals from the plurality of receiving modules. Becomes
Each of the plurality of receiving modules includes a quadrature demodulation unit that generates a two-phase signal from a radio signal by quadrature demodulation, a detector that detects the two-phase signal generated by the quadrature demodulation unit, and a quadrature demodulation unit. A digital filter for filtering the two-phase signals by a predetermined tap gain to improve the signal-to-noise ratio to a predetermined level or more; and an extraction unit for extracting the amplitude from the two-phase outputs output from the digital filter. A diversity receiving device, comprising: an arithmetic unit for weighting the output of the detector with the output from the extraction unit. 3. A plurality of antennas, a plurality of receiving modules provided in each of the plurality of antennas for receiving signals by the same time division two-way communication, and diversity control based on signals from the plurality of receiving modules. The plurality of receiving modules each include a quadrature demodulation unit that generates a two-phase signal from a radio signal by quadrature demodulation, and a detection unit that detects the two-phase signal generated by the quadrature demodulation unit. , A digital filter for filtering the two-phase signals generated by the quadrature demodulation unit using the preamble pattern of the time-division bidirectional communication frame as a tap gain, and the amplitudes extracted from the two-phase outputs output from the digital filter. And an arithmetic unit for weighting the output of the detector with the output from the extraction unit. Diversity receiver that. 4. A plurality of antennas, a plurality of receiving modules provided in each of the plurality of antennas for receiving signals by the same spread spectrum communication, and diversity control based on signals from the plurality of receiving modules. And a despreading unit that despreads the two-phase signals generated by the orthogonal demodulation unit. Section, a detection section that performs detection from the signal from the despreading section, an extraction section that extracts the amplitude of the output output from the despreading section, and the output of the detector is weighted by the output from the extraction section. A diversity receiving device, which comprises: 5. The diversity control according to claim 1, wherein the diversity control by the control unit is maximum ratio combining diversity control performed by combining the weighted signals. Receiver. 6. The diversity control by the control unit is a selective combining diversity control for selecting a signal having the largest signal among the weighted signals. Diversity receiver. 7. The extraction unit adds the value of the two-phase output output from the transversal filter or the despreading unit to the maximum value of each signal and 1/2 of the minimum value of each signal. The diversity receiver according to any one of claims 1 to 6, wherein the amplitude is extracted by doing so.