JPH062841U - Synthetic diver receiver - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a synthetic diver receiver capable of obtaining an output signal without multipath distortion even when there is a large amount of multipath interference in only one of the received signals. [Structure] Received signal S received by antennas 1, 1 '
i and Si ′ are signals S1 and S at the front ends 2 and 2 ′.
The signal S1 is converted into 1 ', is input to the IF signal combiner 6 as signals S2 and S2' through the IF amplifier circuits 3 and 3 ', and the signal phases are combined in phase to obtain an output S0. Also, the signals S2, S
2'with the AM detection circuits 5 and 5 ', envelope signals S3 and S3'
And the peak value is held by the peak hold circuits 7 and 7 '. However, in this case, the peak hold circuit 7, 7 '
The peak value holding operation of 1 has an arbitrary discharge time constant that discharges with time. Then, the AGC is performed with reference to the output signals S5, S5 'of the peak hold circuits 7, 7'.
The gains of the IF amplifier circuits 3 and 3'are controlled by the circuits 4 and 4 '.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diversity system receiver, and more particularly, to a composite input signal control of an FM composite diver receiver.

[0002]

[Prior art]

 FIG. 5 is a block diagram showing the configuration of the combined input signal control unit of the conventional combined diver receiver. In FIG. 5, 1, 1'is an antenna, 2, 2'is a front end, 3, 3'is an IF amplifier, 4, 4'is an automatic gain control circuit (hereinafter referred to as an AGC circuit). 5, 5 ′ are AM detection circuits, and 6 is an IF signal synthesizer.

In FIG. 5, received signals Si and Si ′ received by antennas 1 and 1 ′ are converted into IF signals S1 and S1 ′ at front ends 2 and 2 ′ and passed through IF amplifier circuits 3 and 3 ′. The signals S2 and S2 'are input to the IF signal synthesizer 6. The IF signal synthesizer 6 synthesizes the IF signal phases of the signals S2 and S2 'in phase to obtain an output S0.

In the above-mentioned conventional method, the AGC circuits 4 and 4'provide the IF amplifier circuits 3 and 3'with auto gain control so that the signals S2 and S2 'have the same amplitude as an average value. I was going. In this auto gain control, the AGC circuits 4 and 4'are filtered at arbitrary cutoff frequencies with reference to the envelope signal S3 and S3 'after the signals S2 and S2' have passed through the AM detection circuits 5 and 5 '. It has a (low-pass filter) and stably controls the gains of the IF amplifier circuits 3 and 3 '. If the received signals Si and Si 'of the antennas 1 and 1'are uncorrelated with respect to the multipath interference, the generation timing of the multipath distortion of the signals S2 and S2' is different in time, so the IF signal A signal without multipath distortion can be obtained at the combined output S0 of the combiner 6.

FIGS. 6 and 7 are diagrams showing changes in the IF output level with respect to time t in the conventional method, and FIG. 6 shows a case where both signals S2 and S2 ′ include many multipath distortions. FIG. 7 shows a case where only S2 contains a lot of multipath distortion, and the average value of the signals S2 and S2 ′ is set as the AGC level V.

[0006]

[Problems to be solved by the device]

 However, as shown in FIG. 7, one of the signals S2 and S2 ′ input to the IF signal synthesizer 6 (S2 in FIG. 7) has a large multipath interference, and the other one (S2 ′ in FIG. 7). If there is little multipath interference, then according to the configuration of the composite input signal control unit of the above-mentioned conventional combining diver receiver, the signal S2 with large multipath interference is larger than the signal S2 'with small multipath interference. A time zone of amplitude occurs.

As a result, even if the signal S2 ′ with few multipaths is combined by the IF signal combiner 6, the output S0 thereof contains a distortion of an intermediate value of the multipath distortions of the signals S2 and S2 ′. However, the advantage of combining the signal S2 ′ with less multipath distortion is halved, and conversely, the distortion is increased as compared with the combined signal S2 ′ with less multipath distortion.

The present invention has been made in view of the above-mentioned drawbacks. In the combined input signal control of the combined diver receiver, even when only one of the received signals has a large number of multipath interference, an output signal without multipath distortion can be obtained. An object of the present invention is to provide a composite input signal control device for a composite diver receiver that can be obtained.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the synthesis diver receiver of the present invention comprises a frequency conversion means for converting the first and second reception signals into predetermined intermediate frequency signals and outputting them, and combining the intermediate frequency signals in phase. A diver receiving means including: an in-phase synthesizing unit, an amplitude detecting unit that amplitude-detects each intermediate frequency signal to obtain a detected signal, and a level control unit that controls each intermediate frequency signal level based on the detected signal. A peak hold control means for extracting the hold signal holding the peak level of the detection signal and outputting it to the level control means, and the level control means uses the hold signal to output each intermediate frequency signal to the same level. It operates so as to be constant at the level, and when the in-phase synthesizing means performs in-phase synthesizing the first and second received signals, the multipath interference state is reduced so that each intermediate frequency is reduced. To control means controls the signal level.

[0010]

[Action]

 With the above configuration, the synthesis diver receiver of the present invention converts the first and second received signals into predetermined intermediate frequency signals by the frequency conversion means and outputs the signals, and the in-phase synthesis means uses the intermediate frequency signals to generate the in-phase signals. And the amplitude detection means amplitude-detects the intermediate frequency signals to obtain a detection signal. Then, the peak hold control means extracts the hold signal holding the peak level of the detection signal and outputs it to the level control means. The level control means operates so as to make each intermediate frequency signal constant at the same level by the hold signal, and multipaths the respective intermediate frequency signal levels when the in-phase synthesis of the first and second reception signals by the in-phase synthesis means is performed. Control to reduce the interference condition.

[0011]

【Example】

 FIG. 1 is a block diagram showing a configuration of a combined input signal control unit of a combined diver receiver according to the present invention. In FIG. 1, 1, 1'is an antenna, 2, 2'is a front end as frequency conversion means, 3, 3'is an IF amplifier, 4, 4'is an automatic gain control circuit (AGC circuit), 5, Reference numeral 5'denotes an AM detection circuit as an amplitude detection means, 6 an IF signal synthesizer as an in-phase synthesis means, 7 and 7'denotes a peak hold circuit as a peak hold control means, an AGC circuit 4 and an IF amplifier. 3. The AGC circuit 4'and the IF amplifier 3'constitute a level control means.

FIG. 2 shows an IF output level with respect to time t in the combined input signal control unit shown in FIG. 1, and FIG. 2A shows a case where both signals S2 and S2 ′ contain multipath distortions of substantially the same amount. 2B shows a case where only signal 2 contains a large amount of multipath distortion.

In FIG. 1, received signals Si and Si ′ received by antennas 1 and 1 ′ are converted into IF signals S1 and S1 ′ at front ends 2 and 2 ′ and passed through IF amplifier circuits 3 and 3 ′. The signals S2 and S2 'are input to the IF signal synthesizer 6. The IF signal synthesizer 6 synthesizes the IF signal phases of the signals S2 and S2 'in phase to obtain an output S0.

Further, the signals S2 and S2 ′ are converted into envelope signals S3 and S3 ′ by the AM detection circuits 5 and 5 ′, and the peak values of the envelope signals S3 and S3 ′ are maintained by the peak hold circuits 7 and 7 ′. To have. However, the peak value holding operation of the peak hold circuits 7 and 7'in this case has an arbitrary discharge time constant for discharging with time. Then, the gains of the IF amplifier circuits 3 and 3'are controlled by the AGC circuits 4 and 4'on the basis of the output signals S5 and S5 'of the peak hold circuits 7 and 7'. As a result, the amplitude peak values of the IF signals S2 and S2 'operate at the same level and become the same as the peak level VP as shown in FIG. As a result, as shown in FIG. 2A, when the signals S2 and S2 'include the same amount of multipath distortion, their peak values become almost equal, and the combined output S0 of the IF signal combiner 6 has It is possible to obtain a signal without multipath distortion.

Further, even when one of the signals S2 and S2 ′ has a large multipath distortion (for example, when only S2 contains a large amount of multipath distortion), as shown in FIG. 2B, both signals S2 and S2 ′ are included. The peak values of are almost the same. As a result, the average value of the signals input to the IF signal combiner 6 becomes larger for the signal S2 ′ with less multipath interference, and the signal S2 with large multipath interference is almost the same as the combined output S0 of the IF signal combiner 6. Since it has no effect, a signal with very little multipath distortion can be obtained as the combined output S0 of the IF signal combiner 6.

FIG. 3 is a circuit configuration example of the peak hold circuits 7 and 7 ′ of FIG. 1, and FIG. 4 is a diagram showing signal input / output characteristics of the peak hold circuit of FIG. 3.

[0017]

[Effect of device]

 As described above, according to the present invention, the operation is performed so as not to synthesize a signal containing many multipath distortion components according to the state of multipath distortion, so that a good output signal can always be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a combined input signal control section of a combined diver receiver according to the present invention.

FIG. 2 is a diagram showing an output level with respect to time in the combined input signal control unit shown in FIG. 1, and a partial diagram A shows a case where two signals include a large amount of multipath distortion, and a partial diagram. B shows the case where only one of the two signals contains a large amount of multipath distortion.

3 is a circuit configuration example of the peak hold circuit of FIG.

4 is a diagram showing signal input / output characteristics of the peak hold circuit of FIG.

FIG. 5 is a block diagram showing a configuration of a combined input signal control section of a conventional combined diver receiver.

FIG. 6 is a diagram showing a time variation of two signals input to an IF signal combiner in the presence of multipath interference.

FIG. 7 is a diagram showing a time variation of two signals input to an IF signal synthesizer when one of the two signals has little multipath interference.

[Explanation of symbols]

1, 1'antenna 2, 2'front end (frequency conversion means) 3, 3'IF amplifier 4, 4 'automatic gain control circuit (AGC circuit) 5, 5'AM detection circuit (amplitude detection means) 6 IF signal synthesis Device (in-phase combining means) 7, 7'Peak hold circuit (peak hold control means)

Claims (1)

[Scope of utility model registration request] 1. A frequency conversion means for converting each of the first and second received signals into a predetermined intermediate frequency signal and outputting the signal.
In-phase synthesizing means for synthesizing the intermediate frequency signals in phase, amplitude detecting means for amplitude-detecting the intermediate frequency signals to obtain a detection signal, and level for controlling the intermediate frequency signal level based on the detection signal A diver receiver comprising control means, wherein the level control means has a peak hold control means for extracting a hold signal holding the peak level of the detection signal and outputting the hold signal to the level control means. , The hold signal operates so as to make each of the intermediate frequency signals constant at the same level, and a multipath interference state is reduced when the in-phase combining means performs in-phase combining of the first and second received signals. A diver receiver characterized by controlling the level of each intermediate frequency signal as described above.