JPH03284027A - Diversity receiver - Google Patents

Abstract

PURPOSE:To prevent a signal from deterioration due to interference by interrupting the signal on one side deteriorated by the influence of an interference wave, and prohibiting the synthesis of a deteriorated signal on one side with the signal consisting of only a desired wave and not being deteriorated on the other side. CONSTITUTION:A synthetic wave signal consisting of the desired wave and the interference wave received with a reception antenna 11 is converted to a signal of intermediate frequency at a receiver 12, and is sent to a phase unit 13 and a correlator 14. The correlator 14 supplies the information of frequency difference and phase difference between a reference signal from a reference signal generator 31 and the component of the desired wave included in the signal of intermediate frequency to the phase unit 13 as a phase control signal. As the components of the interference wave included in the signal of intermediate frequency are present more, the level of the phase control signal is decreased relatively compared with a case when it is the signal of intermediate frequency consisting of only the desired wave. A level detector 15 monitors the level of the phase control signal from the correlator 14, and sends an output stopping signal to an attenuator 16 when the relevant level goes less than a value set in advance at the level detector 15, and prohibits the passage of the signal by controlling the attenuator 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a diversity receiving device that receives radio signals using a plurality of receiving antennas and performs synthesis processing on the output signals of the respective antennas to perform high-quality communication. .

(Prior Art) FIG. 2 is a block diagram showing a conventional diversity receiving device. In this figure, 11.21 is the receiving antenna, 12
．． 22 is a receiver, 13 and 23 are phase shifters, 14 and 24 are correlators, 31 is a reference signal generator, 32 is a combiner, 33 is a demodulator, and 34 is an output terminal. The operation of this conventional diversity receiving device will be explained below.

The two radio signals received by the receiving antennas 11.21 each enter the receivers 12.22, are down-converted to intermediate frequencies, and are amplified to a constant level by amplifiers with automatic gain adjustment functions in the receivers 12, 22. and sent to the phase shifter 13.23 as an intermediate frequency signal. Phaser 1
3.23 each receives the phase control signal from the correlator 14.24, and performs phase control so that the frequency and phase of each intermediate frequency signal are equal to the frequency and phase of the reference signal. The intermediate frequency signal is sent to a synthesizer 32. The two intermediate frequency signals sent to the combiner 32 are in-phase combined and sent to the demodulator 33, where the signal is demodulated into a baseband signal and output to the output terminal 34. The phase control is performed by the reference signal generator 3
1, a correlator 14.24, and a phase shifter 13.23.

The reference signal generator 31 is composed of an intermediate frequency band carrier signal generator and a modulator, takes in the baseband signal that is the output of the demodulator 33, modulates the carrier signal with this baseband signal, and generates a reference signal. An estimated reproduction signal of the signal transmitted from the transmitting side is generated. Correlator 1
4.24 each consists of a multiplier and a low-pass filter, and receives the intermediate frequency signal from the receiver 12.22 and the reference signal from the reference signal generator 31, and receives the signal from the multiplier. The product of the intermediate frequency signal from the device 12.22 and the reference signal is 1 and passed through the low frequency r-wave device to generate a phase signal having information on the frequency difference and phase difference between the reference signal and the intermediate frequency signal. Phaser 13 as a control signal.
The 0 phase shifters 13 and 23 output to the respective terminals 23 and 23 are multipliers that multiply the phase control signal from the correlators 14 and 24 and the intermediate frequency signal from the receiver 12. The two intermediate frequency signals are controlled to have the same frequency and phase as the reference signal, respectively, so that the two intermediate frequency signals have the same frequency and phase. These two intermediate frequency signals having the same frequency and phase are combined in phase by a synthesizer 32, and demodulated into a baseband signal by a demodulator 33 to provide high quality communication.

(Problems to be Solved by the Invention) In the conventional diversity receiving device described above, when the radio wave signal received by the receiving antenna 11 is interfered with by an interference wave, the signal entering the receiver 12 is a combination of the desired wave and the interference wave. It becomes a composite signal. This composite signal is converted to an intermediate frequency band and amplified by the receiver 12, and then sent to the phase shifter 13 and the correlator 14. The correlator 14 correlates the reference signal from the reference signal generator 31 with the composite signal from the receiver 12 to generate a phase control signal and outputs it to the phase shifter 13.
Since the phase control signal is generated only by the correlation between the desired wave and the reference signal, the more interference waves are included in the composite signal, the lower the level of the phase control signal becomes. The phase shifter 13 uses the phase control signal whose level has been lowered to control the composite signal so that it becomes equal to the frequency and phase of the reference signal, but the interference wave component remains and the level of the composite signal has also become lower. I end up.

The composite signal controlled by the phase shifter 13 is obtained by combining the uninterfered signal radio waves received by the receiving antenna 21 with the signal controlled by the phase shifter 23 by the synthesizer 32, and demodulating by the demodulator 33. It is output as a baseband signal from the output terminal 34, but since this signal contains interference wave components, it is compared to a signal obtained by demodulating only the signal radio waves that are not affected by interference received by the receiving antenna 21 into a baseband signal. This results in a degraded signal.

As explained above, the conventional diversity receiving device is
Even when one signal radio wave is interfered with by an interference wave, the demodulated signal is degraded due to the influence of the interference wave, and the quality is inferior to when receiving signal radio waves that are not interfered with by one receiving antenna. (Means for Solving the Problem) The diversity receiving device of the present invention converts a received radio wave signal into an intermediate frequency signal, and converts the phase of the intermediate frequency signal to an externally supplied signal. a plurality of receivers that operate according to the phase of a reference signal;
A synthesizer that inputs signals of multiple intermediate frequencies output from the synthesizer, synthesizes the signals, and outputs the synthesized signal, and a synthesizer that inputs the synthesized signal output from the synthesizer and demodulates the synthesized signal. and a reference signal generator that receives the demodulated signal output from the demodulator and generates and outputs the reference signal, the receiver comprising: , an antenna that receives a radio wave signal, a receiver that converts the radio signal into an intermediate frequency signal and outputs it, and inputs the reference signal and the intermediate frequency fr) signal output from the receiver, and those 2. a correlator that detects and outputs a phase difference and a signal level difference between two signals; and a correlator that detects and outputs a phase difference and a signal level difference between two signals; a phase shifter that outputs an intermediate frequency signal with phase difference compensated; an attenuator that inputs the intermediate frequency signal output from the phase shifter and outputs it to the synthesizer; and a signal level output from the correlator. and a level detector that inputs the difference and outputs an output stop signal to the attenuator to stop outputting the signal from the attenuator if the signal level difference is larger than a preset value. It is characterized by

(Example) Next, the present invention will be explained in detail with reference to Examples.

FIG. 1 is a block diagram showing an embodiment of the present invention. In this figure, 11.21 is a receiving antenna, 12.22 is a receiver, 13.23 is a phase shifter, 14°24 is a correlator, and 15
．． 25 is a level detector, 16° is an attenuator, 31 is a reference signal generator, 32 is a combiner, 33 is a demodulator, and 34 is an output terminal. It is a diversity receiver equipped with a level detector 1.5.25 and an attenuator 16°26, and a receiving antenna 112.
1. When receiving signal radio waves that are not interfered with, the operation is the same as that of the conventional diversity receiving device.

Here, it is assumed that a combined wave of the desired wave interfered with the interference wave and the interference wave arrives at the receiving antenna, and only the desired wave arrives at the receiving antenna 21. The desired radio wave signal received by the receiving antenna 21 is converted into an intermediate frequency signal by the receiver 22, and is converted into an intermediate frequency signal by the phase shifter 23 and the correlator 24 by the reference signal generator 31. Same as the intermediate frequency reference signal from! A combined radio wave signal consisting of a desired wave and an interference wave that is controlled to have two frequencies and the same phase, passes through the attenuator 26 without attenuation, and is sent to the combiner 32, while being received by the receiving antenna 11. is converted into an intermediate frequency signal by the receiver 12 and sent to the phase shifter 13 and correlator 14. Correlator 14
supplies information on the frequency difference and phase difference between the reference signal from the reference signal generator 31 and the desired wave component included in the intermediate frequency signal to the phase shifter 13 as a phase control signal. The more interference wave components included in the intermediate frequency signal, the lower the level becomes relative to the intermediate frequency signal containing only the desired wave. (When the levels of the desired wave and the interference wave are equal, the level of the phase shifter m signal is 17r when there is only the desired wave.2) The level detector 15 detects the level of the phase control signal from the correlator 14. The level is monitored [7] and the level is detected by the level detector 16.
When the signal becomes lower than a preset value, an output stop signal is sent to the attenuator 16 to control the attenuator 16 so that the signal does not pass through the attenuator 16.9 In other words, due to the influence of interference waves, The distorted output signal from the phase shifter 13 is blocked by the attenuator 16 to prevent it from being combined with the signal radio wave of the desired wave received by the receiving antenna 21 by the multiplexer 32, and then by the demodulator 33. This prevents signal deterioration due to interference waves appearing in the demodulated baseband signal.

Further, the same result will be obtained if the receiving antenna 11 receives only the desired wave and the receiving antenna 21 receives the desired wave and the interference wave.

Furthermore, when the receiving antennas 11 and 21 both receive a desired radio wave signal, the combiner 32 combines the two signals into a received signal, compared to the case where a single receiving antenna receives the radio wave signal. You can get a high quality received signal.

(Effects of the Invention) As explained in detail above, according to the present invention, one signal degraded by the influence of interference waves is blocked, and one signal that is not degraded and the other signal that is not degraded by only the desired wave are separated. Since the signal is not combined with the signal, deterioration of the signal due to interference can be prevented as a result. Furthermore, when both signals are not affected by interference waves, since both signals are combined, a received signal of higher quality can be obtained than when using only one signal.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional privacy receiving device, and FIG. 2 is a block diagram showing an embodiment of the present invention. 11.21... Reception antenna, 12.22... Receiver, 13.23... Phase shifter, 14.24... Correlator, 15.25... Level detector, 16.26... ...Attenuator, 31...Reference signal generator, 32...Synthesizer,
33... Demodulator, 34... Output terminal.

Claims (1)

[Claims] A plurality of receivers that convert received radio wave signals into intermediate frequency signals and output the intermediate frequency signals in accordance with the phase of a reference signal supplied from the outside, and the plurality of receivers. a synthesizer that inputs multiple intermediate frequency signals output from each of the machines, synthesizes the signals, and outputs the synthesized signal; and a synthesizer that inputs the synthesized signal output from the synthesizer and demodulates the synthesized signal. A diversity receiving device comprising a demodulator that outputs a demodulated signal, and a reference signal generator that receives the demodulated signal output from the demodulator and generates and outputs the reference signal. A receiving antenna, a receiver that converts the radio signal into an intermediate frequency signal and outputs it, and inputs the reference signal and the intermediate frequency signal output from the receiver, and calculates the phase difference between these two signals. A correlator that detects and outputs a signal level difference, and an intermediate frequency signal output from the receiver and a phase shift difference output from the correlator are inputted to generate an intermediate frequency signal that compensates for the phase difference. An output phase shifter, an attenuator that inputs the middle cylinder frequency signal output from the phase shifter and outputs it to the synthesizer, and a signal level difference output from the correlator that inputs the signal level difference. A diversity receiving device comprising: a level detector that outputs an output stop signal to the attenuator to stop signal output from the attenuator when the value is larger than a preset value.