SU985968A1 - Device for receiving discrete frequency-modulated signals - Google Patents

Description

(S) DEVICE FOR ACCEPTING DISCRETE

FREQUENCY-MANIPULATED SIGNALS

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The invention relates to radio and can be used in data transmission systems, in particular, in radio control.

A device for receiving discrete frequency-manipulated signals is known. ,

The purpose of the invention is to improve the premise resistance.

To this end, an adder, a first multiplier, I subtract the 1st block and the second multiplier, the band-pass filter and the amplitude limiter, connected in series, the output of which is T | connected to the first inputs of the ne emnozhiteley each channel, the outputs of bandpass filters are connected to inputs of the first multiplier, whose output is connected to the first input deciding unit, a second input of which

15 is connected to the second output of the synchronization unit, the input of which is connected to the first input of the second multiplier, to the second input of which the output of the frequency synthesizer is connected, while

Claims (2)

20 additional outputs of the pseudo-random sequence generator are connected to the inputs of the adder and subtractive unit, the outputs of which are connected 398 respectively to the second inputs of the multipliers of each of the channels. The decision block consists of a serially connected integrator with a reset and a threshold block, the inputs of the integrator with a reset being the inputs of the decision block, the output of which is the output of the threshold block. The drawing shows a structural electrical circuit of the proposed device. A device for receiving discrete frequency-manipulated signals contains a pseudo-random sequence generator 1, frequency synthesizer 2, first multiplier 3, bandpass filter j amplitude limiter 5, second multiplier 6, two channels 7 and 8, each of which consists of multiplier 9 and bandpass filter 10, a decisive block 11, consisting of a threshold block 12 and an integrator with a reset 13, a subtracting block 14, a synchronization block 15, an adder 16. The device works as follows. The frequency synthesizer 2, in accordance with the control code from generator 1, generates a reference multi-frequency signal, which is fed to the first input of the second multiplier 6, to the second input of which the received signal arrives. At the output of the second multiplier 6, a single and frequency pseudo-random signal is obtained, which through a band-pass filter k and an amplitude limiter 5 is fed to the first inputs of multipliers 9 of both channels 7 and 8, to the second inputs of which the sum M1 + MD and correspondingly the difference of the Ml-MO code sequences received at the second and third outputs of the generator 1. The output signals of these multipliers through the band-pass filters 10 from both channels 7 and 8 are fed to the first multiplier 3 and then through the integrator with the reset 13 and the threshold unit 12 decision block 11 on the way out. As a result of such processing, the dependence of the signal comparison result on the relative change in channel gains is eliminated. A signal to you during the course of the device in its most general form,. ., .., z. (Z8X) - (2BxMo) 3, where is the transmission coefficient; Z0y- input signal; - code sequences. Unlike the prototype when using quadratic detectors, (Z, M) -K (Z, M) Thus, the proposed device provides a higher noise immunity for receiving discrete complex frequency-manipulated signals by eliminating the effect of unbalancing the correlation processing of received signals on decision result. Introduction of a normalized level before dual-channel processing of a pseudo-random signal reduces the dynamic range of received signals, which also leads to an improvement in noise immunity in the case of pulsed or spectrum-centered interference. The noted quality eliminates the need to develop special measures to ensure the strict identity of the channels for processing received signals, which will expand the scope of application of broadband systems in the national economy. Claim 1. A device for receiving discrete frequency-manipulated signals, comprising a decision block, a serially connected synchronization unit, a pseudo-random sequence generator and a frequency synthesizer, and two channels, each of which consists of a serially connected multiplier and band-pass filter, which differs from , in order to improve noise immunity, the adder, the first multiplier, the subtraction unit and the second end-device, serially connected, are introduced into it; liter and amplitude limiter, the output of which is connected to the first inputs of the multipliers of each channel, the outputs of the bandpass filters of which are connected to the inputs of the first multiplier, the output of which is connected to the first input secondary block, the second input of which is connected to the second output of the synchronization unit, the input of which is connected to the first input the second multiplier, to the second input of which the output of the frequency synthesizer is connected, while the additional outputs of the pseudo-random sequence generator are connected to the input mi adder and subtractive unit, the outputs of which are connected respectively to the second inputs of the multipliers of each channel. 2. The device according to claim 1, wherein the decision block consists of a sequentially connected reset integrator and a threshold block, the inputs of the integrator with a jumper being the inputs of the decision block whose output is; output threshold block. Sources of information taken into account in the examination 1. Dickson R.K. Broadband systems. M., Sw., 1979, p. 162 (prototype).