JPH10107714A - Receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the receiver in which the effect of reception waveform distortion due to Rayleigh fading onto a differential coding modulation signal is relaxed. SOLUTION: Phase difference calculation sections 4-1, 4-2 calculate a phase difference between an input signal to a reception section 3-1 and a signal having been received before a prescribed time, and amplitude ratio calculation sections 5-1, 5-2 calculate an amplitude ratio of the input signal to the reception section 3-1 to a signal having been received before a prescribed time. A weight control section 7 measures power of the input signals to the reception sections 3-1, 3-2, and decides the weight given to the amplitude ratio calculation sections 5-1, 5-2 depending on the measurement result. A synthesis section 8 synthesizes the outputs of the amplitude ratio calculation sections 5-1, 5-2 with the weight decided by the weight control section 7. An output of the synthesis section 8 is given to a differential amplitude shift keying(DASK) demodulation section 9, where the signal is converted into a digital data series. On the other hand, outputs from the phase difference calculation sections 4-1, 4-2 are given to an adder 1, where they are simply synthesized and the result is given to a differential phase shift keying(DPSK) demodulation section 10, in which the sum is converted into a digital data series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system for transmitting a signal by, for example, a differential coding modulation method
The present invention relates to a diversity receiver that alleviates the influence of waveform distortion, and more particularly, to a receiver that aims to reduce the influence of distortion due to Rayleigh fading and to simplify the configuration.

[0002]

2. Description of the Related Art In a radio communication system, signal waveform distortion is caused by a poor propagation environment such as Rayleigh fading. In such a propagation environment, it is necessary to take measures for alleviating distortion of the signal waveform, such as waveform shaping by an equalizer or the like, and application of a modulation method resistant to propagation distortion. Among them, a differentially coded phase modulation (hereinafter referred to as DPSK) system in which information is carried on a phase difference between transmission signals is often used in a mobile radio communication system.

In the DPSK system, the original digital data sequence can be demodulated by detecting the phase difference between transmission signals transmitted at two different times, so that it is not necessary to accurately receive the phase of the transmission signal. Therefore, in the DPSK method, there is no need to perform synchronous detection for performing carrier recovery on the received signal, and it is sufficient to perform delay detection for detecting a phase difference from a signal before a predetermined time. When demodulation is performed by delay detection, the bit error rate characteristics of the demodulated digital data sequence are lower than when synchronous detection is performed. However, delay detection does not require carrier recovery that is difficult in a mobile reception environment. The configuration is simplified. In addition, if the transmission time difference between the two signals that provide the phase difference information is sufficiently shorter than the period of the signal waveform distortion, the correlation between the two signals increases, so that the influence of the phase distortion can be ignored.

In recent years, it has become necessary to wirelessly transmit large-capacity information such as data, image signals, and digital broadcasts. If broadband transmission is attempted using a DPSK signal, since the amplitude of all signal points is equal, as a result of multileveling, the Euclidean distance between adjacent signal points on the complex plane is reduced, and reception characteristics are extremely deteriorated. Generally 8D
PSK is said to be the limit. Increasing the signal amplitude,
The Euclidean distance between signal points increases, but requires a large amount of power.

Therefore, in order to achieve wideband transmission without greatly increasing the transmission power, a differentially coded modulation method based on an amplitude ratio (hereinafter, DASK method) and the above-described DPSK method have been proposed.
It has been studied to use the DAPSK scheme, which is a combination of these schemes, as the modulation scheme of a wireless communication system. DA
In the transmitter adopting the PSK method, information is carried on the amplitude ratio and the phase difference, and in the receiver, DASK demodulation and DPSK demodulation are separately performed on the received signal to reproduce data. DA
When the PSK scheme is used, the average transmission power can be smaller than that of the DPSK scheme with the same transmission speed.

However, in a poor environment such as a mobile reception environment typified by Rayleigh fading, there is a problem that the above-described conventional DAPSK receiver greatly deteriorates the bit error rate characteristics.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a receiving apparatus capable of alleviating deterioration of an error rate characteristic due to signal waveform distortion such as Rayleigh fading. I do.

[0008] Specifically, an object of the present invention is to provide a receiving apparatus capable of more effectively performing diversity reception for differentially encoded amplitude modulation.

It is another object of the present invention to provide a receiving apparatus capable of more effectively performing diversity reception in a modulation system that combines differentially encoded phase modulation and differentially encoded amplitude modulation.

Another object of the present invention is to provide a receiving apparatus capable of realizing the above object with a simpler configuration.

[0011]

In order to achieve the above object, a receiving apparatus according to the present invention comprises: a diversity receiving means for obtaining a plurality of branch outputs; and a phase difference before and after each of the branch outputs. Calculating means for calculating the amplitude ratio, a combining means for weighting and calculating the calculated amplitude ratios, and a demodulating means for obtaining a demodulated signal based on the respective phase differences and the synthesis result.

As a branch configuration method for obtaining a plurality of branch outputs, spatial diversity is typical. However, diversity using polarization, angle, and the like may be used. The number of branch outputs may be two or more. For example, by providing two or more antennas or the like, a diversity receiving unit can be configured.

The calculating means includes, for example, for a phase difference, a delay unit for delaying the branch output, a conjugate signal generation unit for generating a conjugate signal from the output of the delay unit, and an output of the conjugate signal generation unit and the branch output. And a multiplier for multiplying by a phase difference calculator. Then, this calculating means multiplies, for example, the signal of the current symbol by the conjugate signal of the previous symbol. However, it is also possible to multiply with the signal of two or more previous symbols.

The calculating means is provided for each branch, for example, with respect to the amplitude ratio, an amplitude ratio calculating section having a delay unit for delaying the branch output and a divider for dividing the branch output by the delay unit output. . For example, the signal of the current symbol is divided by the signal of the previous symbol. However, it is also possible to divide by the signal of two or more previous symbols.
The weighting of each amplitude ratio signal can be performed based on, for example, the signal-to-noise ratio of the input signal between the branches or the power ratio of the input signal. The reference signal for weighting is
For example, each branch output may be used directly. However, the output of each calculation means may be used. In this case, for example, when the calculating means has a delay device as described above, it can be used as a reference signal for weighting the output of each delay device with respect to the phase difference or the amplitude ratio.

The demodulation means performs, for example, demodulation of the DAPSK method.

According to the present invention, it is possible to more effectively perform diversity reception for differentially encoded amplitude modulation by weighting and combining the respective amplitude ratio signals and demodulating them. As a result, it is possible to alleviate the deterioration of the error rate characteristic due to signal waveform distortion such as Rayleigh fading.

Note that weighting may be performed on the phase difference signal. For example, if the respective phase differences are combined, the weights are consequently weighted. However, needless to say, weighting is not necessary.

According to a second aspect of the present invention, there is provided a receiving apparatus comprising:
In a receiving apparatus for receiving and demodulating a transmission signal on which information is carried by an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal, a signal received by each antenna at a first time and a second Phase difference calculation means for calculating a phase difference with a signal received at time, and an amplitude ratio for calculating an amplitude ratio between a signal received at a first time and a signal received at a second time at each of the antennas Calculating means, first synthesizing means for synthesizing each phase difference calculated by the phase difference calculating means, and second synthesizing means for synthesizing while weighting each amplitude ratio calculated by the amplitude ratio calculating means,
Demodulating means for demodulating a result of the synthesis by the first synthesis means and a result of the synthesis by the second synthesis means.

According to the present invention, each phase difference signal calculated by the phase difference calculation means is synthesized, so that each phase difference signal is weighted as a result, and each amplitude ratio signal is weighted and synthesized. . As a result, it is possible to more effectively perform diversity reception in a modulation scheme combining differentially encoded phase modulation and differentially encoded amplitude modulation. As a result, it is possible to alleviate the deterioration of the error rate characteristic due to signal waveform distortion such as Rayleigh fading.

According to a third aspect of the present invention, there is provided a receiving apparatus comprising:
In a receiving apparatus for receiving and demodulating a transmission signal on which information is carried by an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal, and each reception signal received at a first time by each antenna. A first multiplying each received signal received at a second time delayed from the first time;
Calculating means, a second calculating means for obtaining a total amount of amplitude values of the calculation results calculated by the first calculating means, and calculating a total amount of power of each received signal received at the first time. A third calculating means for dividing the total amount of the electric power by a calculation result of the second multiplying means, a synthesizing means for synthesizing each multiplication result calculated by the first calculating means,
And demodulation means for demodulating based on the result of division by the calculation means and the result of synthesis by the synthesis means.

According to a fourth aspect of the present invention, there is provided a receiving apparatus comprising:
In a receiving apparatus for receiving and demodulating a transmission signal on which information is carried by an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal, and each reception signal received at a first time by each antenna. A first multiplying each received signal received at a second time delayed from the first time;
Calculating means, a second calculating means for calculating a total amount of amplitude values of the calculation results calculated by the first calculating means, and calculating a total amount of power of each received signal received at the second time. A third calculating unit that divides a total amount of amplitude values of a calculation result of the second multiplying unit by a total amount of the electric power, and a combining unit that combines respective multiplication results calculated by the first calculating unit. Demodulation means for demodulating based on the result of division by the third calculation means and the result of synthesis by the synthesis means.

For example, in the invention according to the second aspect, for example, a divider is required for calculating each amplitude ratio. The divider generally complicates the circuit configuration.

According to the third and fourth aspects of the present invention, the configuration is such that the division only needs to be performed once in the entire arithmetic processing, thereby simplifying the configuration. And this claim 3 and 4
In the invention described above, similarly to the invention according to claim 2, each phase difference signal is weighted as a result by combining the calculated phase differences, and each amplitude ratio signal is weighted and combined. Therefore, diversity reception can be performed more effectively and with a simple configuration in a modulation scheme combining differentially encoded phase modulation and differentially encoded amplitude modulation.

[0024]

FIG. 1 is a diagram showing a configuration of a DAPSK diversity receiver according to one embodiment of the present invention.
Here, a configuration of a diversity receiver in a case where signals that are differentially coded and modulated simultaneously by two antennas 2-1 and 2-2 are received is shown. However, it is also possible to configure to perform diversity reception with three or more antennas. The two antennas 2-1 and 2-2 simultaneously receive signals that have been differentially coded and modulated by a digital data sequence, and receive signals as branch outputs are received by respective receiving units 3-1 and 3-2. Is input to

Each of the receiving sections 3-1 and 3-2 includes a phase difference calculating section 4-1 and 4-2 and an amplitude ratio calculating section 5-1 and 5-, respectively.
The input signal of the receiving section 3-1 is input to the phase difference calculating section 4-1 and the amplitude ratio calculating section 5-1. The input signal of the receiving section 3-2 is input to the phase difference calculating section 4--1. 2 and the amplitude ratio calculation unit 5-2.

Each of the phase difference calculators 4-1 and 4-2 calculates a phase difference from a signal received a predetermined time ago, for example, a signal received one symbol before, and calculates each of the amplitude ratio calculators 5-1 and 5-2. −
In step 2, an amplitude ratio with a signal received a certain time ago, for example, a signal received one symbol before, is calculated. Each receiving unit 3-
The input signals to 1, 3 and 2 are input to the weighting synthesis unit 6.

The weighting / synthesizing unit 6 includes a weight control unit 7 and a synthesizing unit 8. The weight control unit 7 includes the receiving units 3-1 and 3
-2 measuring the power or signal-to-noise ratio of the input signal,
The weight value of each of the amplitude ratio calculation units 5-1 and 5-2 is determined according to the measurement result. The synthesis unit 8 includes an amplitude ratio calculation unit 5-1,
The output of 5-2 is weighted by the weight value determined by the weight control unit 7 and synthesized. At this time, the weight control unit 7 is removed,
The outputs of the amplitude ratio calculation units 5-1 and 5-2 may be simply combined. The output of the synthesizing unit 8 is converted by the DASK demodulating unit 9 into a digital data sequence.

On the other hand, the outputs of the phase difference calculators 4-1 and 4-2 are simply synthesized by the adder 1, and converted into a digital data series by the DPSK demodulator 10.

FIG. 2 shows a configuration example of the amplitude ratio calculation units 5-1 and 5-2. In the amplitude ratio calculation units 5-1 and 5-2, the amplitude of the input signal is detected by the absolute value calculation unit 11, and is input to the delay unit 13 that delays the signal for a certain time. And the divider 12
Divides the output of the absolute value calculation unit 11 by the output of the delay unit 13.

FIG. 3 shows an example of the configuration of the phase difference calculators 4-1 and 4-2. The input signals of the phase difference calculation units 4-1 and 4-2 are
The signal is delayed for a predetermined time by the delay unit 13 and is converted into a conjugate signal by the conjugate signal generation unit 14. The multiplier 15 multiplies the input signals of the phase difference measurement units 5-1 and 5-2 by the output of the conjugate signal generation unit 14, and outputs a phase difference signal from a signal before a predetermined time.

FIG. 4 shows a configuration example of the weight control section 7. The weight control unit 7 includes a power measuring device 16 and a weight calculator 17. The power measuring device 16 includes the receiving units 3-1 and 3-
2 is measured, and a weight calculator 17
Calculates the weight of the input signal to the combining unit 8 based on the measurement result of the power meter 16 and outputs the calculated value. Weight calculator 1
7, the weight of the output of the amplitude ratio calculator of the receiving unit having a large power measured by the power meter 16 is 1, and the weight of the output of each of the amplitude ratio calculators 5-1 and 5-2 is 1. The weight of the unit output may be set to 0, or a value proportional to the measurement result of the power measuring device 16 may be set.

FIG. 5 shows another example of the configuration of the weight control unit 7.
Here, the weight is calculated based on the measurement result of the signal-to-noise ratio of the input signal. The weight control unit 7 includes a signal-to-noise ratio measurement unit 18 and a weight calculator 17. The signal-to-noise ratio measurement unit 18 measures the signal-to-noise ratio of the input signal of the weight control unit 7. The weight control unit 17 calculates and outputs a weight based on the measurement result of the signal-to-noise ratio. In this case, as in the weight control section shown in FIG. 4, the weight value of the output of the amplitude ratio calculation section of the reception section having a large signal-to-noise ratio is 1, and the weight values of the outputs of the other amplitude ratio calculation sections are 1 0
Or a value proportional to the measurement result of the signal-to-noise ratio.

FIG. 6 shows an example of a configuration in which a signal before a predetermined time is used as a weight control signal. In this example, the delay units 13-2 and 13-4 in the amplitude ratio calculation units 5-1 and 5-2 are used.
Is used as an input signal of the weight control unit 7.

The input signal to the weight control unit 7 is not limited to only the outputs of the delay units 13-2 and 13-4 in the phase difference calculation units 4-1 and 4-2.
2-2, outputs of the conjugate signal generators 14-1 and 14-2 in the phase difference calculators 4-1 and 4-2, and a delay unit 13-
1, 13-3, the outputs of the absolute value calculation units 11-1 and 11-2 in the amplitude ratio calculation units 5-1 and 5-2, and the like may be used. Further, a combination of these outputs may be used as an input signal to the weight control unit 7. FIG. 7 shows a configuration example in which the outputs of the delay units 13-1 and 13-3 in the phase difference calculation units 4-1 and 4-2 are used as input signals to the weight control unit 7.

Next, another embodiment of the present invention will be described.

In this embodiment, an example will be described in which the circuit configuration of the diversity receiver is simplified when a signal before a predetermined time is used as an input signal of the weight control unit. In the diversity receiver having N reception unit, a time k, signal r _k of receiver _m, When _m, the amplitude ratio at time k and k-1 of the signal in the receiving unit m is, | r _{k, m} | / | Rk _{-1, m} |. When this numerator and denominator are multiplied by | r ^* _{k, m} | _, respectively, | rk _{, m} | ² // rk _, mr ^* _{k-1, m} |

Assuming that the weight of the amplitude ratio calculators 5-1 and 5-2 of the receiver m is α _m , the output signal of the synthesizer 8 is

(Equation 1) It is expressed as At this time, the magnitude of the weight α _m is calculated at time k−1
Based on the power ratio of each receiver

(Equation 2) Then, equation (1) is expressed as follows.

[0038]

(Equation 3) Also, the amplitude ratio of the signals at times k and k-1 in the receiving unit m |
_{r k, m | / | r} k-1, m | of the molecule and each of the denominator | r ^*
_When multiplied by _{k-1, m} |, the result is | rk _, mr ^* _{k-1, m} | / | rk _{-1, m} | ² . At this time, the output signal of the synthesizing unit 8 has a weight α _m
Using,

(Equation 4) It is expressed as At this time, the magnitude of the weight α _m is calculated at time k−1
Based on the power ratio of each receiver

(Equation 5) Then, Equation (4) is expressed as follows.

[0039]

(Equation 6) Defining the weights in this way simplifies the circuit configuration of the diversity receiver. This is because the number of divisions requiring a complicated circuit configuration is only one. FIG.
Is a specific example of a diversity receiver having a simplified circuit configuration. The received signals received by the antennas 2-1 and 2-2 are input to the receiving units 3-1 and 3-2, respectively. The receiving units 3-1 and 3-2 each include a phase difference calculating unit 4.
-1, 4-2, power calculation units 19-1, 19-2, and absolute value calculation units 11-1, 11-2.

After the input signals of the receiving units 3-1 and 3-2 are delayed for a fixed time by the delay units 13-1 and 13-2, they are converted into conjugate signals by the conjugate signal generating units 14-1 and 14-2, respectively. Is done. The multipliers 15-1 and 15-2 are connected to the conjugate signal generation unit 1
The outputs of 4-1 and 14-2 are multiplied by the input signals of the receiving units 3-1 and 3-2. The outputs of the multipliers 15-1 and 15-2 are added by the adder 1-1, and the DPSK demodulation unit 10
It is SK demodulated and converted to a digital data sequence. The outputs of the multipliers 15-1 and 15-2 are output to the absolute operation unit 1
Absolute values are calculated in 1-1 and 11-2, respectively, and the adder 1
-2 is added.

Further, the received signals received by the antennas 2-1 and 2-2 are subjected to power measurement by the power calculators 19-1 and 19-2, and then combined by the adder 1-3. Divider 1
2 divides the output of the adder 1-3 by the output of the adder 1-2, and the output is DASK-demodulated by the DASK demodulator 9;
It is converted to a digital data sequence.

As shown in FIG. 9, the conjugate signal generator 1
4-1 and 14-2 are input to the power calculators 19-1 and 19-1.
9-2, and may be combined by the adder 1-3. In this case, the divider 12 divides the output of the adder 1-2 by the output of the adder 1-3, and the output is DASK-demodulated by the DASK demodulator 9 and converted into a digital data sequence.

Therefore, in these receivers, the divider is 1
(The divider 12), and the circuit configuration is simplified.

Next, an application example of the receiving apparatus of the present invention will be described.

Use of orthogonal frequency division multiplexing (hereinafter, OFD) as a transmission system for digital terrestrial broadcasting is being studied. In order to transmit a high-definition video signal in a band limited by the OFD signal, it is necessary to increase the transmission speed of each subcarrier of the OFDM signal.
Use of 16 DAPSK having six types of transmission symbols as a modulation scheme has been studied. An example in which the receiving device of the present invention is applied to this system will be described.

FIG. 10 shows an example in which the receiving apparatus of the present invention is applied to a diversity receiver that demodulates the differential coded modulation {FD} signal in the time axis direction for each OFDM subcarrier signal. The signals received by the antennas 2-1 and 2-2 are
The guard time is removed by the guard time removing units 20-1 and 20-2, respectively, and fast Fourier transform (hereinafter, FF) is performed.
Τ) The signals are converted into frequency spectrum signals by the units 21-1 and 21-2. When DAPSK modulation is performed between adjacent subcarriers in the OFDM signal, the FFT unit 21-1,
The parallel frequency spectrum signals respectively output from 21-2 are converted into serial signals by parallel / serial converters 22-1 and 22-2. Outputs of the respective parallel / serial converters 22-1 and 22-2 become input signals of the diversity receiver 23 according to the present invention, and the original digital data sequence is demodulated. As the diversity receiver 23 according to the present invention, for example, there are the receivers shown in FIGS. 1 and 6 to 9.

FIG. 11 shows an example in which the present invention is applied to a diversity receiver that demodulates the differential coded modulation {FD} signal in the time axis direction for each OFD subcarrier signal.

The outputs of the antennas 2-1 and 2-2 are subjected to guard time elimination by guard time elimination units 20-1 and 20-2, and then converted into frequency spectrum signals by FFT units 21-1 and 21-2. Is done. And each FFT unit 21
The same frequency spectrum signal output from -1, 21-2 is input to the same diversity receiver. This OFD
In the diversity receiver for M signals, the diversity receiver 23-1 according to the present invention for signals of respective frequencies is used.
~ 23-}, diversity reception of the {FD} signal becomes possible. However, the delay amount of the delay unit included in each diversity receiver is equal to OFDΜsymbol length.

The OFD diversity receiver shown in FIG.
Since a plurality of diversity receivers are required, if the number of outputs of the FF # section increases, this circuit configuration is not practical. Therefore, FIG. 12 shows an O / O according to the present invention that can demodulate a differentially coded modulation OFD signal with one diversity receiver.
5 shows an FD @ diversity receiver.

As in the receiver shown in FIG. 11, the output of each of the antennas 2-1 and 2-2 is supplied to a guard time removing section 20-.
After the guard time is removed in 1, 20-2, the signal is converted into a frequency spectrum signal in FF # units 21-1 and 21-2. The outputs of the FF units 21-1 and 21-2 are converted into serial signals by the parallel / serial converters 22-1 and 22-2, respectively, and the outputs of the diversity branches are demodulated by the diversity receiver 23. However, there is no correlation between the signals before and after the serial-converted signal, and since the signals separated by the FDM signal length are differentially coded and modulated, the delay amount of the delay unit in the diversity receiver 23 is {FD} It is equal to the signal length.

FIG. 13 shows an OF in which each subcarrier is differentially coded in the time axis direction, with the vertical axis representing the bit error rate and the horizontal axis representing the signal energy to noise energy ratio per bit.
The simulation result of the mobile reception characteristic of the DΜ signal is shown. The simulation was performed with 8192 FFT points, OF
DM effective symbol length 1ms, guard time 0.25ms,
Carrier frequency 300Myuitaz, the Doppler frequency f _d is 30Hz Rayleigh fading, 100 [mu] s delay time τ is delayed wave 1 wave, desired wave power to interference wave power D / U is 0dB
And a diversity receiver that uses the received signal power as the input signal of the weight control unit, and uses the output of the amplitude ratio calculation unit of the receiving unit with the larger input signal power as the input signal of the DASK demodulator. The receiving system, the received signal power is used as the input signal of the weight control unit, and the weighting proportional to the power of the input signal is multiplied by the output of each amplitude calculating unit to synthesize the output.The output of each amplitude ratio calculating unit is simplified. The bit error rate characteristics of the equal gain combining diversity scheme for combining are shown. From FIG. 13, it is expected that any of the diversity schemes of selection, equal gain, and combining according to the present invention can greatly improve the characteristics in a mobile reception environment. In particular, the combining diversity according to the present invention can obtain an error rate of about 1%. It turns out to be very effective.

[0052]

As described in detail above, diversity receiving means for obtaining a plurality of branch outputs, calculating means for calculating a phase difference and an amplitude ratio before and after each of the branch outputs, and calculating each of the calculated amplitude ratios. By providing the weighting and combining means and the demodulation means for obtaining a demodulated signal based on the respective phase differences and the result of the combination, it is possible to more effectively perform diversity reception for differentially encoded amplitude modulation, It is possible to alleviate the degradation of the error rate characteristic due to signal waveform distortion such as Rayleigh fading.
Also, in a receiving apparatus for receiving and demodulating a transmission signal on which information is carried by an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal;
Phase difference calculating means for calculating a phase difference between a signal received at a time and a signal received at a second time, respectively, a signal received at a first time and a signal received at a second time at each of the antennas An amplitude ratio calculating means for calculating an amplitude ratio of each of the above, a first synthesizing means for synthesizing each of the phase differences calculated by the phase difference calculating means, and weighting each of the amplitude ratios calculated by the amplitude ratio calculating means. And a demodulating means for demodulating the result of the synthesis by the first combining means and the result of the synthesis by the second combining means. Diversity reception can be performed more effectively in a modulation scheme that combines coded amplitude modulation, and degradation of error rate characteristics due to signal waveform distortion such as Rayleigh fading can be reduced.

Further, in a receiving apparatus for receiving and demodulating a transmission signal on which information is carried according to an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal, and each antenna receiving the transmission signal at a first time. First calculating means for multiplying each received signal and each received signal received at a second time delayed from the first time, and an amplitude value of a calculation result calculated by the first calculating means Second calculating means for calculating the total amount of power of each received signal received at the first time, and calculating the total amount of power by the second amount.
A third calculating means for dividing by the calculation result of the calculating means, a synthesizing means for synthesizing each multiplication result calculated by the first calculating means, a dividing result by the third calculating means, and Having a demodulating means for demodulating based on the synthesis result, or a receiving device for receiving and demodulating a transmission signal on which information is loaded by an amplitude ratio and a phase difference, a plurality of antennas for receiving the transmission signal, First calculating means for multiplying each received signal received at a first time by each antenna by each received signal received at a second time delayed from the first time, and the first calculation Means for calculating the total amount of amplitude values of the calculation result calculated by the means, and calculating the total amount of power of each received signal received at the second time, and calculating the result of the second multiplication means. Amplitude value Third calculating means for dividing the total amount by the total amount of the electric power, synthesizing means for synthesizing each of the multiplication results calculated by the first calculating means, and a result of the division by the third calculating means and the synthesizing means. Providing demodulation means for demodulating based on the synthesis result enables diversity reception to be performed more effectively and with a simple configuration in a modulation scheme combining differentially encoded phase modulation and differentially encoded amplitude modulation. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a diversity receiver according to one embodiment of the present invention.

FIG. 2 is an exemplary block diagram illustrating a configuration of an amplitude ratio measurement unit according to the embodiment.

FIG. 3 is a block diagram showing a configuration of a phase difference measuring unit according to the embodiment.

FIG. 4 is a block diagram showing a configuration of a weight control unit in the embodiment.

FIG. 5 is a block diagram showing another configuration of the weight control unit in the embodiment.

FIG. 6 is a block diagram showing a configuration of a diversity receiver according to another embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a diversity receiver according to another embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a diversity receiver according to another embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a diversity receiver according to another embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of an OFD diversity receiver to which the present invention is applied.

FIG. 11 is a block diagram showing another configuration of the OFD diversity receiver to which the present invention is applied.

FIG. 12 is a block diagram showing another configuration of an OFD diversity receiver to which the present invention is applied.

FIG. 13 shows bit error rate characteristics of OFDM diversity reception according to the present invention.

[Explanation of symbols]

 1,1-1 to 1-3 ... Adder 2-1 and 2-2 ... Antenna 3-1 and 3-2 ... Receiver 4-1 and 4-2 ... Phase difference calculation Units 5-1 and 5-2 Amplitude ratio calculation unit 6 Weight combination unit 7 Weight control unit 8 Synthesis unit 9 DASK demodulation unit 10 DPSK demodulation unit 11 , 11-1, 11-2 ... Absolute value calculation unit 12, 12-1, 12-2 ... Divider 13, 13-1 to 13-4 ... Delay device 14, 14-1, 14 -2 Conjugate signal generator 15, 15-1, 15-2 Multiplier 16 Power measuring device 17 Weight calculator 18 Signal-to-noise ratio measuring unit 19-1 , 19-2 ... power calculation units 20-1, 20-2 ... guard time removal units 21-1, 21-2 ... fast Fourier transform units 22-1, 22-2 ... Column / serial converter 23 ......... diversity receiver according to the present invention

Claims (4)

[Claims] 1. Diversity receiving means for obtaining a plurality of branch outputs, calculating means for calculating a phase difference and an amplitude ratio before and after each of the branch outputs, and combining means for weighting and combining the calculated amplitude ratios And a demodulating means for obtaining a demodulated signal based on each of the phase differences and the synthesis result. 2. A receiving apparatus for receiving and demodulating a transmission signal on which information is carried according to an amplitude ratio and a phase difference, comprising: a plurality of antennas for receiving the transmission signal; Phase difference calculating means for respectively calculating a phase difference between the signal and the signal received at the second time; and an amplitude ratio between the signal received at the first time and the signal received at the second time by each antenna. An amplitude ratio calculating means for calculating each; a first synthesizing means for synthesizing each phase difference calculated by the phase difference calculating means; and a second synthesizing while weighting each amplitude ratio calculated by the amplitude ratio calculating means. And a demodulating unit for demodulating a result of the combination by the first combining unit and a result of the combination by the second combining unit. 3. A receiving apparatus for receiving and demodulating a transmission signal on which information is carried according to an amplitude ratio and a phase difference, comprising: a plurality of antennas for receiving the transmission signal; First calculating means for multiplying each received signal and each received signal received at a second time delayed from the first time, and an amplitude value of a calculation result calculated by the first calculating means And a third calculating means for calculating the total amount of power of each of the received signals received at the first time, and dividing the total amount of power by the calculation result of the second multiplying means. Calculation means; synthesis means for synthesizing each multiplication result calculated by the first calculation means; and demodulation means for demodulating based on the division result by the third calculation means and the synthesis result by the synthesis means. Features to Receiving device. 4. A receiving apparatus for receiving and demodulating a transmission signal on which information is carried according to an amplitude ratio and a phase difference, comprising: a plurality of antennas for receiving the transmission signal; First calculating means for multiplying each received signal and each received signal received at a second time delayed from the first time, and an amplitude value of a calculation result calculated by the first calculating means A second calculating means for calculating a total amount of power of each of the received signals received at the second time, and calculating a total amount of amplitude values of a calculation result of the second multiplying means by the total amount of power. A third calculating means for dividing by the following, a combining means for combining the multiplication results calculated by the first calculating means, and a demodulation based on a result of the division by the third calculating means and a result of the combining by the combining means. With demodulation means A receiving device.