SU1392622A1 - Device for receiving signals in multichannel coherent communication system - Google Patents

Abstract

The invention relates to telecommunications and radio communications. The purpose of the invention is to improve the noise immunity of reception. The unit contains on the transmitting side a block 2 signaling unit of code 2, a source m of additional synchronous messages 3, a phase handler 4, a terminal unit 5, a sync block 6, on the receiving side includes a receiving unit 7 and N channels 8, each of which contains a matched filter 9 and a decisive block 10, an adder 11, an output phase meter 12, a phase decoder 13, a sync block 14, and a communication line 19. To achieve the goal, the device has a stator pulse former 17, a synchro shaper 18, and in every channel except first Go, - meter phase difference 15 and switch 16. 1 Il. % (L

Description

The invention relates to electrical radio communications and can be used in wired, radio, and radio relay and space lines of communication, $

The aim of the invention is to increase the noise immunity of the reception.

The drawing shows a structural electrical diagram of the proposed device. 1Q

The device contains on the transmitting side a block I of generating a group signal of code 2, a source of 3 m additional synchronous messages, a phase manipulator 4, a terminal (5 block 5, a sync block 6, on the receiving side includes a receiving block 7 and N channels 8, each of which contains a matched filter 9 and a deciding unit 10, an adder J1, an output 20 phase meter 12, a phase decoder J3, a sync block 14, a phase difference meter 15, a switch 16, a strobe pulse generator 17, a clock generator 18 and a communication line 19 25.

The device operates as follows,

On the transmitting side k (k = 3, 4, '

5, ...) the main binary synchronous 30 channel signals consisting of symbols 1 and 0 are fed to the information inputs of the group signal generation unit 1, and 2k biorthogonal 35 binary code sequences with a duration equal to the duration of information signals are generated in the code generator 2 characters, so that each of the main compressed channels corresponds to a certain 40 pair of code sequences - a sequence and its inversion. At the signal output of block 1, code messages are formed of majority sealed phase-shifted '/ 45 n (0, G) signals. Information of additional channels synchronous with the main channels is introduced by phase manipulation of the code messages in the phase manipulator with possible phase shift q'η / Ζ '' (η = 0,1, ...,

- 1). In the sync block 6, the first input of which receives the carrier frequency from the second output of block 1, and the second input contains information about the 55 end times of the code sequences from the code generator 2, the clock signals are generated, which are introduced into the hollow group signal in the terminal block 5. Then, the complete group signal is transmitted on the communication line 19. On the receiving side p. the output of the receiving unit 7, the signal is transmitted to the channels 8, in each of which a matched filter 9 is matched with the corresponding signals of a certain pair of code sequences formed on the transmitting side. A sync pulse is generated at the output of the sync block J4 at time T, corresponding to the moment of the end of the code sending at the output of the matched filter 9, accurate to the phase fractions of the carrier oscillation of the transmitter, and three pulses of duration создаются are generated in the clock generator 18 with a time shift relative to the value of T by 0, G, 2 ί (where <is the period of the carrier frequency), respectively, at the first, second and third outputs. The output voltages of the matched filters 9 are gated in the deciding blocks by 10 pulses of the shaper 17 at the moment of time T _c = T + 2® + · Ρ · ι / _ΠΜ / _2н , where ψ _ΠΜ is the measured phase value of the total signal, and depending on the sign of the voltage this time at the outputs of the decision blocks 10 at a time T> 3 ΐ, determined by the trailing edge of the signal at the third output of the clock generator 18, symbols J, or 0 of the main channels are formed. The allocation of information of additional channels and the determination of the gating times T _c is as follows. On the time interval T - T + ΐ specified by the pulse at the first output of the shaper 18 clock pulses, in each of the meters 15 of the phase difference, the phases of the output signal of the matched filter 9 i-ro and the first channel 8 are compared. If the phase difference is within the range - "/ 2 to + 17/2, then the output of the matched filter 9 is connected via a switch 16 to the adder 11 directly, otherwise, inverted. The output signals of all the switches 16 are added to the adder 11, the output signal of which is supplied to the output phase meter 12, in which the initial phase of the total signal is measured at the second output of the driver 18 (T +?) ~ - (Τ + 2ΐ) if _nu relative to the phase of the carrier oscillation generated in this block by the pulse of the sync block 14. Moreover, the same decisions are made if the values of Lf _nM are in the range (n 17/2 ^ + + (1? / 2- ') or (ηί? / 2 ^№) + E + (· 7ί / 2 ^ΜΜ). According to the results of decoding phase formed additional code channel. Based on the signals acting on the second output of generator 18, a strobe pulse is generated at time point T _c = T 2 +? + (t / 2?). </ _nu.

Claims (2)

Claim A device for receiving signals in a multi-channel coherent communication system, the receiving block containing the output of which is connected to N channels, each of which consists of a matched filter and a decision block, the output of which is an output of the channel, and the input of the matched filter by its input, the clock output of the receiving block is connected to the input a sync block, the output of which is connected to the synchro input of the output phase meter, as well as an adder, the output of which through the output phase meter is connected to the phase decoder, the output of the matched filter A channel of the first channel is connected to one of the inputs of the adder, characterized in that, in order to increase the noise immunity of the reception, a synchronizer of ^J pulses, a driver of strobe pulses are introduced, and in each channel, except for the first, a difference meter is connected in series phases and a switch, the outputs of ₁₀ switches of all channels are connected to other inputs of the adder, in each channel the output of the matched filter is connected to the input of the decision block, the gate input and the clock (g input of which are connected respectively to the outputs of the clock generator, in each channel, except for the first, the output of the matched filter is connected to the first input of the meter 2 by the phase difference and the input of the switch, the output of the matched filter of the first channel is connected to the second inputs of the phase difference meters of all channels whose sync inputs are connected to the output of the clock generator, the output of the clock is connected to the input of the clock driver, the outputs of which are connected respectively to the sync inputs of the pulse gate 30 and a phase meter, the output of which is connected to the input of the strobe pulse former.