JPH05276078A - Space diversity receiver - Google Patents

Abstract

PURPOSE:To improve both S/N and waveform distortion of each multi-carrier with simple circuit configuration and to synthesize reception signals through synchronization. CONSTITUTION:A branch circuit 1 branches a reception signal Sb into two, and they are respectively sent to phase shift circuits 2, 3. Synthesis circuits 4, 5 respectively synthesize output signals of the phase shift circuits 2, 3 and reception signals Sa, Sc to generate synthesis signals S1, S2. Multi-carrier distribution circuits 6, 7 separate n-sets of multi-carriers included respectively in the synthesis signals S1, S2. Synchronization synthesis circuits 11-1n synthesize reception signals for each multi-carrier through synchronization. Level detection circuits 21-2n, 31-3n, detect respectively the level of the n-sets of multi-carriers and send signals L21-2n, L31-L3n representing the level. Spectrum deviation control circuits 8, 9 control respectively the phase shift circuits 2, 3 to minimize the level deviation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a space diversity receiver, and in particular, it combines three reception signals including n (n is an integer of 2 or more) received by three-sided antennas into each multicarrier. The present invention relates to a space diversity receiving device that outputs each of.

[0002]

2. Description of the Related Art A conventional space diversity receiver of this type, as shown in FIG. 2, includes a plurality (n) of signals Sa, Sb, Sc respectively received by three-sided antennas (not shown). Individual) multi-carriers Sa1 to S
multicarrier distribution circuits 1a, 1b, 1c for extracting an, Sb1 to Sbn, Sc1 to Scn, first synchronous combining circuits 101 to 10n and second synchronous combining circuits 201 to 20n for synchronously combining two input signals. It has and.

Here, the first synchronous synthesis circuits 101 to 10
n synchronously combines multi-carriers Sa1 to San and Sb1 to Sbn corresponding to each other. That is, the first synchronous synthesizing circuit 101 synthesizes the multicarriers Sa1 and Sb1, and similarly, the first synchronous synthesizing circuit 10n synthesizes the multicarriers San and Sbn.

Further, the second synchronous synthesis circuits 201 to 20n
Is a composite output signal S2 for each multicarrier by combining the multicarriers Sc1 to Scn and the output signals S101 to S10n of the first synchronous combining circuits 101 to 10n, respectively.
01 to S20n are transmitted.

By the way, each synchronous synthesizing circuit has a phase shift circuit 9 for varying the phase of one of the two input signals.
1, a phase difference detection circuit 92 that detects a phase difference between two signals to be combined, a control circuit 93 that controls a phase shift circuit according to the phase difference, and a combination circuit 94 that combines the two signals. ing. The synchronous synthesizing operation of the first synchronous synthesizing circuit is set to be faster than that of the second synchronous synthesizing circuit so that the synthesizing operation converges.

[0006]

In the conventional space diversity receiving apparatus described above, the multi-carriers of the signals received by the three-sided antennas are synchronously combined, so that the S / N of each multi-carrier can be improved. However, when waveform distortion occurs due to coherent fading or the like, it cannot be suppressed.

As a means for suppressing and synthesizing such waveform distortion, there is a minimum amplitude deviation synthesizing circuit for synthesizing by controlling the phase shift circuit so that the frequency spectrum distribution becomes flat with respect to the center frequency. However, when such a minimum amplitude deviation synthesizing circuit is applied to a space diversity receiving device having a three-sided antenna, a minimum amplitude deviation synthesizing circuit is required for each multicarrier, which causes a problem that the circuit configuration becomes complicated. is there.

An object of the present invention is to provide a space diversity receiver which can improve the S / N and waveform distortion of each multicarrier with a simple circuit configuration.

[0009]

A space diversity receiving apparatus of the present invention combines three reception signals including n (n is an integer of 2 or more) multi-carriers received by three-sided antennas to synthesize each multi-wave. A space diversity receiving device for outputting each carrier, comprising:
A branch circuit for branching one of the two received signals into two, and first and second phase shift circuits for controlling the phases of the signals branched by the branch circuit in accordance with the first and second control signals, respectively. Of the three received signals and the other two received signals and the output signals of the first and second phase shift circuits, respectively, the first and second combining circuits, and the first combining circuit. A first multi-carrier distribution circuit that receives an output signal and separates and outputs the n multi-carriers respectively, and an output signal of the second combining circuit that separates the n multi-carriers and separates the n multi-carriers, respectively. A second multi-carrier distribution circuit for outputting, and n synchronous synthesizing circuits for synchronously synthesizing each of the n multi-carriers output by the first and second multi-carrier distributing circuits for each multi-carrier, First level detecting means for detecting respective levels of n multi-carriers output by the first multi-carrier distribution circuit, and n multi-carriers respectively output by the second multi-carrier distribution circuit. The second level detecting means for detecting the level of the first multi-carrier and the first level detecting means for minimizing the level deviation of the n multi-carriers detected by the first level detecting means.
And a means for generating the second control signal so that the level deviation of the n multi-carriers detected by the second level detecting means is minimized. There is.

[0010]

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

FIG. 1 is a block diagram showing an embodiment of the present invention, in which received signals Sa, Sb, Sc respectively including a plurality (n) of multicarriers are synchronously combined to synthesize n multicarriers. The case where the output signals S31 to S3n are obtained is shown.

The branch circuit 1 branches the received signal Sb into two and sends it to the phase shift circuits 2 and 3. The synthesis circuit 4 is
The signal that has passed through the phase shift circuit 2 and the received signal Sa are combined,
The composite signal S1 is sent to the multicarrier distribution circuit 6.
Similarly, the synthesizing circuit 5 synthesizes the signal passed through the phase shift circuit 3 and the received signal Sc, and sends the synthesized signal S2 to the multicarrier distribution circuit 7. Multi-carrier distribution circuit 6,7
Extracts n multi-carriers included in each of the combined signals S1 and S2, and multi-carriers S11 to S1 are extracted.
n, S21 to S2n.

The synchronous synthesizing circuits 11 to 1n are provided corresponding to n multi-carriers, and receive the corresponding multi-carriers extracted by the multi-carrier distributing circuits 6 and 7, respectively, and perform synchronous synthesizing. That is, the synchronous synthesizing circuit 11 receives the multi-carriers S11 and S21, synchronously synthesizes them, and outputs the synchronous synthetic output signal S31. Similarly, the synchronous synthesizing circuit 1n includes multi-carriers S1n and S2.
When n is received, synchronous synthesis is performed and a synchronous synthesis output signal S3n is transmitted.

Here, each of the synchronous synthesis circuits 11 to 1n has a phase shift circuit 41 for varying the phase of one of the input multicarriers S21 to S2n and a branch circuit 42 for branching the multicarriers. , 43, narrow band filters 44 and 45, AGC amplifier circuits 46 and 47,
It has a phase comparison circuit 48 for detecting a phase difference, a control circuit 49 for controlling the phase shift circuit 41 according to the phase difference, and a combining circuit 50 for combining two multicarriers in phase.

By the way, the narrow band filters 44 and 45 are
The control circuit 49 is provided to extract the spectrum component in the band of each multicarrier, and the control circuit 49 controls the phase shift circuit 41 by the extracted spectrum component.

On the other hand, the level detection circuits 21-2n, 31-
3n detects the level of each of the extracted spectrum components, and indicates the signals L21 to L2n and L31 to indicate the level.
L3n is sent to the spectrum deviation control circuits 8 and 9, respectively. Here, the deviation state of the levels detected by the level detection circuits 21 to 2n indicates the spectrum distribution state of the combined signal S1, and the deviation state of the levels detected by the level detection circuits 31 to 3n indicates the combined signal S2. Shows the spectrum distribution state of.

The spectrum deviation control circuits 8 and 9 receive the signals L21 to L2n and L31 to L3n indicating the levels, respectively, and the phase shift circuits 2 and 3 are designed to minimize the level deviation.
Control each. In this way, the S / N of each multicarrier can be improved by performing the synchronous synthesis by the synthetic circuits 4 and 5 and the synchronous synthesis circuits 11 to 1n.
Waveform distortion can also be reduced.

[0018]

As described above, according to the present invention, 3
One of the two received signals is branched into two and passed through the phase shift circuit, respectively, and then combined with the other two received signals of the three received signals to generate first and second combined signals. , N multicarriers are separated by the first and second multicarrier distribution circuits, respectively, and then synchronously synthesized for each multicarrier by the n synchronous synthesis circuits. In this case, the levels of n multi-carriers respectively separated by the first and second multi-carrier distribution circuits are detected, and the phase shift circuit is controlled so that the level deviation is minimized. Since synchronous synthesis can be performed in a state in which the deviation of the spectrum distribution of the synthesized signal is minimized, there is an effect that both the S / N and waveform distortion of each multicarrier can be improved with a simple circuit configuration.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an example of a conventional space diversity receiver.

[Explanation of symbols]

1, 42, 43 Branch circuit 2, 3, 41 Phase shift circuit 4, 5, 50 Combiner circuit 6, 7 Multi-carrier distribution circuit 8, 9 Spectrum deviation control circuit 11-1n Synchronous combiner circuit 21-2n, 31-3n Level Detection circuit 44, 45 Narrow band filter 48 Phase comparison circuit Sa, Sb, Sc Received signal S1, S2 Combined signal S11 to S1n, S21 to S2n Multicarrier S31 to S3n Multicarrier combined output signal L21 to L2n, L31 to L3n Multicarrier Signal indicating the level of

Claims (1)

[Claims] 1. n (n) received by a three-sided antenna
Is a space diversity receiving apparatus that combines three reception signals including two or more multi-carriers and outputs each multi-carrier, and a branching circuit that branches one of the three reception signals into two. When,
First and second phase shift circuits that control the phases of the signals branched by the branch circuit in accordance with the first and second control signals, respectively, and two other received signals of the three received signals. First and second combining circuits for respectively combining the output signals of the first and second phase shift circuits, and for separating the n multi-carriers by receiving the output signals of the first combining circuit A first multi-carrier distribution circuit for outputting each, a second multi-carrier distribution circuit for receiving the output signals of the second combining circuit, separating the n multi-carriers, and outputting the separated multi-carriers, respectively. The n multi-carriers output from the second multi-carrier distribution circuit are synchronously synthesized for each multi-carrier n
Synchronization synthesizing circuits, first level detecting means for detecting respective levels of the n multicarriers respectively output from the first multicarrier distributing circuit, and the second level detecting means.
Second level detecting means for detecting the respective levels of the n multicarriers output by the multicarrier distributing circuit of n, and n detected by the first level detecting means.
Means for generating the first control signal so that the level deviation of the multi-carriers is minimized, and the level deviation of the n multi-carriers detected by the second level detecting means is minimized. And a means for generating a second control signal.