JPH02253727A - Diversity reception circuit - Google Patents

Abstract

PURPOSE:To eliminate necessity to detect a reception level and to improve the quality of a transmission characteristic by detecting phase information from plural angle modulation waves, comparing the phase information, selecting single data out of plural frequency detection data or weighting the respective frequency detection data, synthesizing the data and outputting the data. CONSTITUTION:Two phase detecting means 3 and 3a outputs two modulation signals to be respectively inputted to modulation signal input terminals 1 and 2, two relative phase data showing a momentary phase with a reference phase signal and two frequency detection data. A phase data comparator circuit 4 compares the two relative phase data as mentioned above and outputs comparison data. Based on the comparison data from the phase data comparator circuit 4, a selecting and synthesizing circuit 5 selects one of the two frequency detection data as mentioned above or weights the above mentioned frequency detection data, synthesizes the data and outputs the data to an output terminal 6. As a result, the adjustment of a reception level detection circuit or a log amplifier having a wide dynamic range is not required and a reception circuit can be simplified.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used for diversity receiving circuits used in wireless transmission, and particularly for improving the transmission characteristics of lines that transmit digital signals using angle-modulated carrier waves. This invention relates to a diversity receiving circuit for improving diversity.

[Conventional technology]

Since wireless communication lines use radio waves as a transmission medium, fading, interference, and the like can cause level fluctuations and phase fluctuations in received signals, which can degrade transmission characteristics. It is known that a diversity reception method is effective against such deterioration of transmission characteristics.

The most typical diversity reception method is a selection diversity reception method in which a fading wave with the highest reception level is momentarily selected and received from among a plurality of fading waves that fluctuate independently of each other. This is based on the fact that the higher the reception level, the higher the S/, N (signal/noise), the smaller the phase fluctuation, and the higher the transmission quality.

FIG. 13 shows a typical conventional two-branch selection diversity receiving circuit. Receivers 38 and 38a are installed at an appropriate distance between the two antennas 39 and 39a so that mutually independent fading waves can be obtained.

As reception level detection means, log amplifiers 33 and 33a are used as intermediate frequency amplifiers. The log amplifiers 33 and 33a are equipped with means for outputting a DC voltage proportional to the decibel value of the received level, and by comparing the output voltages of the two log amplifiers 33 and 33a with the level comparator 35, the received level can be compared. It can be performed. Further, based on the comparison output, the diversity switch 35 selects the detection output from the detector 37 or 37a with the higher reception level. As a result, the detection output with high S/N and little phase fluctuation is constantly output to the output terminal 36.
can be obtained. In FIG. 13, 31 and 32 are a modulation signal input (1) terminal and a modulation signal input (2) terminal.

[Problem that the invention seeks to solve]

However, when the reception level is used as information for branch determination, the following drawbacks occur.

First, as a characteristic of the log amplifiers 33 and 33a, level detection performance over a wide range of reception levels is required. However, in actual log amplifiers, the level detection characteristics often become saturated in regions where the reception level is particularly high or particularly low, and deviations from the straight line occur even in intermediate regions. In such a region, even though the reception levels between the branches are different, the difference in output voltage becomes small, making it impossible to accurately compare the reception levels. Additionally, because it is difficult to match the level detection characteristics of log amplifiers between branches over a wide range of reception levels, errors occur in the reception level comparison results in areas where the degree of discrepancy is significant, reducing the diversity effect. .

Next, in FIG. 13, the log amplifier 33 of one branch
Considering the case where the detection characteristics of this branch have deteriorated due to increased distortion due to poor adjustment or deterioration of the wave detector 37a or the wave detector 37a, comparing only the received levels and switching to the wave detector 37a may be a better solution. There are disadvantages that the S/N ratio decreases and phase fluctuation increases.

Furthermore, diversity based on comparison of received levels is not effective when transmission characteristics deteriorate due to causes other than a decrease in received levels. For example, considering the effect on co-channel interference, - For boat fishing, the higher the reception level, the less the influence of interference waves, so a diversity effect can be obtained. However, since the level of the interference wave also fluctuates due to fading, the higher the received level is, the lower the received level is (b), as shown in Figure 14 (a).
There are cases where /I (desired wave level/interference wave level) becomes small and the probability of error occurrence increases. In such a case, there is a drawback that even if diversity is used by comparison of received levels, the effect cannot be obtained.

Furthermore, when the received input signal levels of the two branches are both low, the received level comparison operates due to thermal noise,
Accurate comparison output of the average reception level cannot be obtained. For example, as shown in FIGS. 15(a), 15(a) and 15(c), when the desired wave level is almost the same but there is a lot of thermal noise,
The level fluctuates depending on the noise vector. If diversity is performed using this comparison output, there is a drawback that the transmission characteristics may be adversely deteriorated.

An object of the present invention is to eliminate the above-mentioned drawbacks, thereby making it possible to obtain a diversity effect without detecting the reception level, and furthermore, to obtain the diversity effect not only against fading but also against all factors that affect the transmission line. The object of the present invention is to provide a diversity receiving circuit that can be obtained.

[Means for solving problems]

The present invention provides a diversity circuit for a communication line that transmits a digital signal using an angle-modulated carrier wave, and is provided with a selection means for selecting a signal with small fluctuation, wherein the selection means selects a plurality of signals corresponding to a diversity method. One or more phase detection means that output a plurality of relative phase data indicating the instantaneous relative phase between the angle modulated wave and the reference phase signal and a plurality of detection data, and a plurality of previous two relative phase data are compared. a phase data comparing means for outputting comparison data; and based on the comparison data from the phase data comparing means, one of the plurality of detected data is selected, or the detected data is weighted and synthesized. It is characterized by comprising a selection/synthesis means.

The present invention also provides a selection means that compares relative phase data indicating the instantaneous relative phase between the angle modulated wave and the reference phase signal, a plurality of phase detection means for outputting detection data, and the plurality of relative phase data. and a phase data comparing means for outputting comparison data using the phase data comparing means, and selecting one of the detected data output from the plurality of phase detecting means or weighting each detected data based on the comparison data from the phase data comparing means. and a selection/synthesis circuit that performs and synthesizes.

Further, the present invention uses, as a selection means, an angle modulated wave that transmits the same data n times with a delay of 7 hours manually, and detects relative phase data indicating the instantaneous relative phase between this angle modulated wave and a reference phase signal, and One phase detection means outputs data, relative phase data of this phase detection means at time t, and relative phase data (k=1.2・, n−1) at (k·τ) hours before time t1. and a phase data comparing means for comparing and outputting comparison data, and based on the comparison data from the phase data comparing means, the time 1. of the phase detecting means is determined. From the detection data at and time i, (k
- τ) It is possible to include a selection/synthesizing circuit that selects one of the detected data of the previous time or weights and synthesizes each detected data.

[Effect]

In the present invention, phase information is detected from a plurality of angle modulated waves whose levels and phases vary independently due to fading etc. using a phase detection means, a phase data comparison means, and a selection/synthesis means, and the phase information is compared. , select a single piece of data from a plurality of pieces of detected data, or weight each piece of detected data and combine it for output. This is based on the knowledge that the phase information has a certain relationship with the transmission characteristics, as shown in FIG. 7, for example.

Thereby, the diversity circuit according to the present invention uses phase information from the angle modulated wave as diversity selection/combining information, so reception level detection is not necessary. Furthermore, since phase information has a direct relationship with transmission characteristics, it is possible to obtain diversity effects not only against fading but also against things that independently degrade transmission characteristics, such as interference and thermal noise.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention.
The case where the number of diversity branches n=2 is shown.

The embodiments of this document describe a diversity circuit that is equipped with a selection means for selecting a signal with small fluctuation in a communication line that transmits a digital signal using an angle-modulated carrier wave, and the features of the present invention are as the selection means. Modulation signal input (]) terminal 1 and modulation signal input (2) terminal 2
two phase detection means 3 and 3a that output two modulation signals manually inputted respectively, two relative phase data indicating the instantaneous relative phase with the reference phase signal, and two detection data; A phase data comparison circuit 4 serves as a phase data comparison means for comparing relative phase data and outputting comparison data, and based on the comparison data from this phase data comparison circuit 4, one of the two detected data is selected. A Q selection/synthesis circuit 5 is included as a selection/synthesis means for selecting or weighting and synthesizing the detected data and outputting the result to an output terminal 6. And phase detection means 3
and 3a respectively include relative phase detection circuits 8 and 8a that output relative phase data, and detection circuits 7 and 7a that output detection data.

Next, the specific configuration and operation of each circuit will be explained.

FIG. 2 is a block diagram showing an example of the phase detection means 3, and the phase detection means 3a is also the same.

The detection circuit 7 is a synchronous detection circuit configured using a PSK signal as an example of an angle modulated wave, and includes multipliers 7-1.
7-2 and 7-3 and low pass filter (LPF)?
-1, 7-5 and 7-6, and π/2 phase shift circuit (
π/2) 7-7, a voltage controlled oscillator (VCO) 7-8, and an identification circuit 7-9, and detects the angle modulated wave using the reproduced carrier wave.

The relative phase detection circuit 8 includes n delay lines (D) 9-1 to 9.
-n, and a sample circuit 10 including (n+1) flip-flops 10-1 to 10-(n+1).

The phase shift circuit 9 uses delay lines 9-1 to 9-n to divide the half period of the reproduced carrier wave into n by using it as a reference phase signal.
is used to output signals 00 to σ7. Next, in the sample circuit 10, those phase-shifted signals C
3-C1 converts the angle modulated wave into flip-flops 10-1 to 1
It samples at O-(T1+1) and outputs the sample output as relative phase data (Qa ""' Q-).

Using the relative phase data, it is possible to determine where the phase of the angle modulated wave is located relative to the phase of the reference phase signal.

The operating principle of the relative phase detection circuit 3 is shown in FIGS. 3(a) and 3(a). For example, if the carrier frequency is 455kHz (1
period -2197,8nsee), each delay line 9-1
If you set the delay amount of ~9-n to 109.9nsec,
A regenerated carrier wave is obtained by shifting the half period of the carrier wave by 18 degrees. With these phase-shifted signals C3-Cll, one period of the carrier wave is 20 as shown in FIG. 3(a).
divided into phase regions. Here, as shown in FIG. 3(b), when the rising edge of the angle-modulated wave signal is located in the phase region shown in the figure, the sample circuit 10 includes flip-flops 10-4 to 1O-(n+1 >, the relative phase data (Qo ""'Q-) becomes 0000111111. This relative phase data (Qo
O""'Q-) differs depending on the phase position of the angle modulated wave, so conversely, this relative phase data (Q, , , ,
, , Q, ), the phase relationship between the angle modulated wave and the recovered carrier wave can be determined.

In addition to being constructed by connecting a plurality of delay lines, a shift register may also be used as the phase shift circuit 9. A specific circuit example of the phase detection means 3 in this case is shown in the fourth section.
As shown in the figure. When using a shift register, first, the voltage controlled oscillator (VCO) in the detection circuit 7. -8 as carrier frequency f. It is configured to be able to output a frequency m times as large as , and to further divide the frequency by m using a frequency divider (1/m) 7-10 to obtain a reproduced carrier wave. Voltage controlled oscillator 7-
If the output signal of 8 is used as the clock of the shift register of the phase shift circuit 9, the recovered carrier wave is used as the clock of the shift register of the phase shift circuit 9.
The output signal can be shifted by one cycle of the -8 output signal. In addition to the flip-flop, the sample circuit 10 also includes t! It can also be constructed using an X-0R circuit and a low-pass filter.

The phase data comparison circuit 4 compares the relative phase data of the phase detection means 3 and the phase detection means 3a, and selects and
The combining circuit 5 selects one of the detected data. As a comparison method, if the range of possible phases at that time is known in advance, the branch with the least deviation from that phase value is selected.

For example, in the case of a signal in ΩPS, the signal phase on the signal space is represented by only four phase points as shown in FIG. Note that even if the QPSK signal is band-limited with a roll-off filter, if only the optimal identification timing is focused, only four phase points will still be shown. If a carrier wave corresponding to one axis or Q axis can be reproduced on the demodulation side, these four phase regions are known. When this SK signal passes through a transmission line where fading or the like exists, the phase varies randomly from four phase points as shown in FIG.

Therefore, it is considered that the larger the phase deviation, the greater the influence of fading. When the number of shifts in the phase region indicated by diagonal lines is measured with respect to the fading frequency, the results are shown in FIG. It can be seen that the larger the fading frequency is, the more frequently the phase fluctuates, and that the influence of fading can be predicted depending on the magnitude of the phase deviation.

The above example shows the case where the phase fluctuates due to fading, but this method can be used not only when the phase fluctuates due to fading, but also when the phase fluctuates due to other factors such as thermal noise and interference.
If the fluctuations are independent in the two branches, a diversity effect can be expected.

The following methods can be considered as methods for branch determination.

(1) Method of determining from bitstream ■ During a certain period of continuous bits (pit stream), measure the number of bits that fluctuate in a phase region that cannot normally be taken, and select the branch with the smaller count value. It is determined that high-quality detection is being performed, and data of that pit stream is selected.However, the pit stream setting method is as shown in Figure 8(a) and υ.
Figure 8 (
1. As shown in C), the data is set while shifting one bit at a time, and the data at the center of the selected pit stream is selected. A possible method is to set each pit stream as shown in FIG. 8 (6) and select data for the entire bit stream.

In addition, the logic opposite to this method is ``a method that measures the number of bits that stay in the originally possible phase region during consecutive bits for a certain period of time, and selects the one with the largest counted value.''
can also be considered.

■ In the case of an angle modulated wave with a certain regularity in phase transition, from the phase data of consecutive bits over a certain period,
It is possible to estimate the phase region where a transition may or may not occur in the next bit. Therefore, it is determined that the branch with the smallest or largest deviation from that phase region in the next bit is being detected with higher quality.

Then, the data of the determined branch at that time is selected.

(2) Method of instantaneously determining each bit Every bit or every few bits, a branch in a phase region close to the originally possible phase region is determined to have been detected with higher quality, and Output data is selected based on the bits used for determination. It is also conceivable to weight each phase region.

FIGS. 9(a), 9(b) specifically show the method (2) above. As shown in FIG. 9(a), weighting numbers are assigned to phase regions on the signal space, and weighting numbers are determined for relative phase data from each phase detection means.

As shown in FIG.
1 and 4-2.

Next, the subtraction circuit 4-3 subtracts the weight numbers of each branch and compares the weight numbers based on the sign bit. Therefore, it is determined that the one with the smaller weight number is closer to the possible phase region, and the detected data from that branch is selected. If the weight numbers are the same, it may be set to either one or the previous detected data.

As mentioned above, the bookcase embodiment does not require a reception level, so a log amplifier is not required, simplifying the circuit and eliminating the need for adjustment. Therefore, the diversity effect can be obtained over a wide range of reception levels.

Further, in the bookcase embodiment, branches are determined based on phase information that is directly related to detection characteristics, so accurate determination can be made and a branch with better characteristics can always be selected. For example, if the receiver deteriorates, the degraded branch may be mistakenly selected when comparing the received levels, but if you use this example, you can always obtain a good diversity effect regardless of the received level. It will be done.

Furthermore, diversity effects can be expected not only against fading but also against other factors that degrade transmission characteristics, such as interference and thermal noise, if the correlation between multiple branches is small. For example, as explained in FIG. 13, when comparing received levels, there are cases where a branch with a small C/I is selected, but if the phases are directly compared as in the bookcase example, it is always possible to select a branch with a small C/I. You can choose a large branch.

Furthermore, as shown in FIG. 15, when both reception levels are low, the reception level comparison may malfunction due to thermal noise. However, in this example, even when there is a lot of thermal noise, the branch that is less affected by the thermal noise vector is always selected, so it is possible to obtain diversity effects even in low-level regions where conventionally there was no diversity effect. .

In the above description of the operation of the second embodiment, a case has been described in which the selection/synthesis circuit 5 operates as a selection circuit, but instead of the detection data, the detection output before passing through the identification circuit is synthesized. A similar configuration can also be made for the case. As a method of combining, the signals are weighted and combined in descending order of the magnitude of the phase deviation or the frequency of phase fluctuation determined by the phase data comparison circuit 4. This weight data can be easily calculated from the output data of each sample circuit 10 using a combinational logic circuit. This can also be converted into an analog value using a D/A converter. Analog multipliers and digital multipliers can be used as synthesis circuits depending on the data format.

Further, as the relative phase detection circuit 8, the configuration shown in FIG. 10 can also be used. Here, the wave was detected using a detection circuit.■
Comparator 8-21 with multi-stage signal and Q signal voltages
~2n and 8-31~3n, or converted into digital data through a ^/ mouth converter. From this data, relative phase data can be obtained by calculation or the like using the calculation circuit 8-1.

As the detection circuit 7, in addition to the synchronous detection circuit, a delay detection circuit shown in FIG. 11 can also be used. This delayed detection circuit is
/2 phase shift circuit π/2)? -11 and multiplier 7-
12 and 7-13, an identification circuit 7-14, and a 1-bit delay circuit 7-15.

Then, by multiplying the manually generated angle modulated wave by a signal delayed by one bit of the data signal by the one-bit delay circuit 7-15, a detected output regarding the phase difference component of the data signal is obtained. In this case, the phase shift circuit 9
A signal obtained by delaying the angle modulated wave by one bit of the data signal is used as the reference phase signal input to the input signal.

Further, in the second embodiment, the number of diversity branches is n=2, but the same effect can be obtained even when the number of diversity branches is n=3 or more.

FIGS. 12(a) and 12(b) are block diagrams showing a second embodiment of the present invention, in which FIG. 12(a) shows the transmitting side and α
)) indicates the receiving side.

The second embodiment has a configuration in which branches are assigned to the receiver itself in the first embodiment, whereas the second embodiment has a configuration called time diversity in which branches are assigned temporally. First, as shown in FIG. 12(a), on the transmitting side, the same data input manually to the data input terminal 21 is sent to the delay circuit (T) 22 with different times, and then sent to the switching circuit 23 multiple times ( (Here, it is assumed to be twice, but three or more times is also possible.) The signal is transmitted via the modulation circuit 24, the transmitter 25, and the antenna 26. For example, data input in the order of Dl, Dl, Dl is D,,D,,D3,DI'XDl'
11 D3' diversity modulated wave. Then, on the receiving side, data when the reception level is high is selected as more accurate data. Although the transmission efficiency is low because the same data is transmitted twice, it has the advantage of requiring only one receiver.

The phase detection means 3 in the second embodiment is the same as one of the circuits shown in the first embodiment, and includes a detection circuit 7 that detects an angle modulated wave and outputs detected data, and a detection circuit 7 that outputs relative phase data. The phase detection circuit 8 includes a phase detection circuit 8. However, as for the human power applied to the modulation signal input terminal 27 of the phase detection means 3,
We are considering an angle modulated wave that transmits the same data twice with a time delay. The relative phase data outputted from the phase detection means 3 is branched into two parts, one directly, and the other delayed by one hour by a delay circuit (τ) 29, and sent to the phase data comparison circuit 4. Comparison is made in the same manner as in one embodiment.

In addition, the detected data is also branched into two, one of which is connected to the delay circuit 2.
8 causes a delay of 7 hours. Then, the phase data comparison circuit 4 and the selection/synthesis circuit 5 select the detected data with the smaller phase deviation, or weight each detected data according to the magnitude of the phase deviation and synthesize the detected data.

The feature of the present invention is that in FIG. 12 et al., a phase detection means 3, a phase data comparison circuit 4, and a selection/synthesis circuit 5 are provided.

Since the second embodiment also does not require a reception level, a log amplifier is not required, and the circuit can be simplified and no adjustment is required, and the range of reception levels in which diversity operates is limited by the log amplifier. This eliminates this problem and allows a diversity effect to be obtained with a wide reception level. Furthermore, since the branch is determined based on phase information that is directly related to the detection characteristics, accurate determination can be made. Therefore, when there is no correlation between multiple branches, a diversity effect can be expected not only against fading but also against other factors that degrade transmission characteristics such as interference and thermal noise.

Furthermore, in the second embodiment, since only one phase detection means is required, the configuration of the diversity circuit is further simplified.

Note that the method of branch determination in the phase data comparison circuit 4 and its circuit, the selection/synthesis circuit 5, the detection circuit 7, and the relative phase detection circuit 8 described in the first embodiment are the same in the second embodiment. Applicable.

〔Effect of the invention〕

As explained above, the present invention uses the phase information of the angle modulated wave as a method for selecting a branch, so that a reception level detection and comparison circuit is not required.

As a result, there is no need to adjust the reception level detection circuit or a log amplifier with a wide dynamic range, which simplifies the reception circuit, and also reduces the diversity effect due to incomplete adjustment of the reception level detection circuit. There is no risk of this occurring. Furthermore, since phase detection can be achieved entirely by digital circuits, no adjustment is required and the reliability is extremely high. There are effects such as

Furthermore, since diversity has an effect not only on fading but also on interference, thermal noise, etc., it is possible to improve the quality of transmission characteristics. From the above, the present invention is applicable to general wireless communication and its effects are extremely practical. Obtaining a diversity effect even with respect to thermal noise means that the receiving sensitivity of the radio equipment increases, and this effect is particularly large in satellite communications where even a slight increase in sensitivity is important.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the phase detection means. FIG. 3(a) is an explanatory diagram of the operating principle of the relative phase detection circuit. FIG. 4 is a block diagram showing another example of the phase detection means. FIG. 5 is an explanatory diagram showing the signal phase of the QPSK signal on the signal space. FIG. 6 is an explanatory diagram showing the phase of a QPSK signal when it passes through a transmission line where fading etc. exist. FIG. 7 is a characteristic diagram showing the frequency of phase fluctuation with respect to fading frequency. FIGS. 8(a) to 8(a) are explanatory diagrams of a branch determination method. FIG. 9(a) is an explanatory diagram showing weighting to phase regions. FIG. 9 is a block diagram showing an example of the phase data comparison circuit. FIG. 10 is a block diagram showing an example of the relative phase detection circuit. FIG. 11 is a block diagram showing an example of the delay detection circuit. FIGS. 12(a) and 12(b) are block diagrams showing a second embodiment of the present invention. FIG. 13 is a block configuration diagram showing a conventional example. FIGS. 14(a) and 14(6) are explanatory diagrams of signal vectors during co-channel interference. FIGS. 15(a) to 15(C) are explanatory diagrams of signal vectors when the reception level is low. 1, 31...Modulation signal input (1) terminal, 2.32...
- Modulation signal input (2) terminal, 3.3a...phase detection means, 4...phase data comparison circuit, 4-1.4-2...
・Combinational logic circuit, 4-3... Subtraction circuit, 5...
Selection/composition circuit, 6.36...output terminal, 7.7a.
・Detection circuit, 7-1 to 7-4.7-12.7-13・
... Multiplier, 7-4 to 7-6 ... Low pass filter,
7-7,? -11...π/2 phase shift circuit (π/2
),? -8 Voltage Controlled Oscillator (VCO), 7-9.7
-14-...Identification circuit, 7-10...Frequency divider (1/m
),? -15...1 bit delay circuit, 8.8a...
・Relative phase detection circuit, 8-1...Calculation circuit, 8-21
~8-2n, 8-31 ~ 8-30... comparator,
9... Phase shift circuit, 9-1 to 9-n... Delay line, 10... Sample circuit, 10-1 to 1O-(n+1
)...Flip-flop, 21...Data input terminal, 22.28.29...Delay circuit, 23...Selection circuit, 24...Modulation circuit, 25...Transmitter, 26.3
9.39a...Antenna, 27...Modulation signal input terminal, 33.33a...Log amplifier, 34...Level comparator, 35...Diversity switch, 37.37
a...Detector, 38.38a...Receiver. Patent Applicant Nippon Telegraph and Telephone Corporation Agent Patent Attorney Nao Ide Kobue Zu Atsushi-Fuun Example's Multiplication Shoulder 1st Q Axis 梠Karikun... 5 Caps Bow 0 Burning Explanation Life Sho 3rd Shoulder 501 Revised (Kuho shoulder 60 credit mo figure feshin 7 round anti-shousho phase 5r eye tan 4 life figure kozu student unprecedented passage W313 mouth (b) 1 Hector figure (mugi impersonation he Luca"f Mr. Case) Iris 1
5 times

Claims (1)

[Claims] 1. A diversity circuit comprising a selection means for selecting a signal with small fluctuation in a communication line that transmits a digital signal using an angle-modulated carrier wave, wherein the selection means is compatible with a diversity method. one or more phase detection means for outputting a plurality of relative phase data indicating instantaneous relative phases between a plurality of angle modulated waves and a reference phase signal and a plurality of detection data; and a plurality of said relative phase data. a phase data comparison means that compares and outputs comparison data, and based on the comparison data from this phase data comparison means,
1. A diversity receiving circuit comprising: selection/synthesis means for selecting one of the plurality of detected data, or for weighting and combining the detected data.