SU760458A1 - Device for automatic correction of linear distortions in communication channels - Google Patents

Description

The invention relates to engineering

communication and can be used for automatic correction of linear distortions in communication channels.

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A device for automatic correction of linear distortions in communication channels, containing on the transmitting side serially connected pseudo-random sequence generator and forming filter, on the receiving side is a sync and harmonic equalizer integrated at the input. The first input of the first discrete H regulator is coefficients and input of the delay element with η taps, moreover, each of the η taps and the output of the delay element are connected respectively to the first 'inputs (n + 1) discrete 2 (offsets of the coefficients, the outputs of which are connected to the inputs of the summing block of the harmonic equalizer, as well as the pseudo-random sequence generator connected in series and forming the ’filter, and the correlator C1].

However, the known device for

Automated linear correction

distortions in communication channels having! E (

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low accuracy and high correction time.

The aim of the invention is to improve the accuracy and reduce the time of correction.

For this, a device for automatic correction of linear distortions in communication channels, containing on the transmitting side serially connected pseudo-random sequence generator and forming filter, on the receiving side — a synchronization unit and harmonic equalizer integrated at the input, the input of which is the first input of the first discrete regulator of diversion coefficients and the input of the delay element with η taps, each of the η taps and the output of the delay element are connected respectively to the first inputs (n + 1) d controllers of the lateral coefficients, the outputs of which are connected to the inputs of the summing block of the harmonic corrector, as well as sequentially connected pseudo-random sequence generator and formative filter, and correlator, on the receiving side, a shift pulse generator, a clock shift unit, a clock generator, an analog numeral 760458

rovoy transducer interface unit, a microprocessor, a negotiating unit, wherein on the receiving side sync block output is connected through a shift clock unit, the other input of which is connected to the output of pseudorandom sequence generator NOSTA ^5, the output of the shaping filter connected serially connected Erez ^ correlator, analog digital converter, interface block, mic-. the processor and the matching unit ko '? the second inputs (n + 1) of discrete regulators of diversion coefficients of the harmonic corrector, the output of the summing block of which is connected to another input of the correlator, the output of the clock-oscillator is connected to other inputs of the analog-digital converter and microprocessor, the other outputs of which are connected to another input of the interface and another input of the matching unit.

The drawing shows a structural electrical circuit of the proposed device.

A device for automatic correction of linear distortions in communication channels on the transmitting side contains a pseudorandom sequence generator 1 and a shaping filter 2, and on the receiving side a synchronization unit 3, a harmonic equalizer 30 4 containing (n + 1) discrete controllers 5 coefficients, delay element 6 and summing unit 7, pseudo-random sequence generator 8, forming filter 9, correlator core 10, shift pulse generator 11, clock shift unit 12, clock generator 13, analog-digital conversion the distributor 14, the conjugation unit 15, the microprocessor 16, and the converting unit 17 - 40.

The device works as follows 067 at once.

The pseudo-random sequence (PSP) from the generator 1 of the pseudo-random 45 sequence enters the shaping filter 2, at the output of which the signal spectrum is close to the spectrum of white noise with a width corresponding to the frequency range of the communication channel. This signal with distortions, determined by the characteristics of the communication channel, is fed to the input of the harmonic equalizer 4 and the input of the synchronization unit 3. The latter provides a pseudo-random sequence ^{3 of the} reference SRP from the generator 8 at the receiving side synchronous with the SRP from the generator 1 of the pseudo-random sequence on the transmitting side, and the clock shift unit 12 produces a clock shift 60 of the reference SRP at times η where η. 1,2,3, ..., determined by the pulses from the generator 11 pulses of the shift. At the output of the shaping filter 9, we have a noise-like 65

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signal correlated with the signal at the output of the harmonic corrector 4.

Both signals are fed to the inputs of the correlator 10, which determines the counts of the cross-correlation function between these signals, located at intervals of time equal to the duration of the memory clock cycle. Using the analog-digital converter 14, the values of these samples are converted into binary numbers, which through the interface unit 15 enter the microprocessor 16. During the shift of the reference memory bandwidth by one period, we get the number of samples equal to the number of pulses in the memory bandwidth. The values of samples in binary form are recorded in the H memory of the microprocessor 16. For white noise, the form of the cross-correlation function _Вз ( ^- ) coincides with the form of the impulse response η ('ϊ') up to a constant factor. Thus, we have N counts of the impulse response communication channel. Digital processing of these quantities in the microprocessor 16 allows us to determine the main value of η (5), which eliminates the need for accurate phasing of the distorted and reference bandwidth and the associated errors. At the same time, the inaccuracy of the moment of determination of the main value does not exceed half the duration of the memory clock cycle and can easily be obtained with the required value by selecting the corresponding memory cycle time. Rationing of sample values by the found value of the main value of the distance-. The necessity of the AGC scheme and the errors associated in the device prototype with the inequality of the levels of the distorted and reference bandwidth at the inputs of the differential amplifier. In digital processing, out of all stored counts of the impulse response, those corresponding to the temporal location relative to the main value are assigned to the taps of the harmonic corrector 4, and the values of the diversion coefficients and the corresponding positions of the discrete regulators 5 of the diversion coefficients are determined by their values.

From the microprocessor 16 commands that establish discrete regulators 5 diversion factors immediately to the desired position, are transmitted through the block 17 approval.

Thus, the proposed device provides automatic correction of linear distortions of communication channels, which allows increasing their capacity and improving communication quality;

increases the accuracy of the correction, due to the elimination of errors from the inaccuracy of phasing of the distorted and reference bandwidth and the inequality of their levels;

reduces the adjustment time of the corrector due to the rejection of the lengthy process of phasing the PSP and iterative.

760458

installation of discrete regulators of diversion factors.

In addition, the implementation of the device can be facilitated, since it eliminates the need for the inclusion of correlators in all branches from the links of the delay line of the harmonic equalizer, which distinguishes it from the prototype.

Claims (1)

Claim (0 A device for automatic correction of linear distortions in communication channels, containing on the transmitting side serially connected pseudo-random sequence generator ^ and a shaping filter, on the receiving side - input synchronized synchronization unit and harmonic equalizer whose input is the first input of the first discrete regulator of diversion coefficients and input the delay element with η taps, each of the n taps and the output of the delay element are connected respectively to the first inputs (n + 1) discrete Knob shunt coefficients, the outputs of which are connected to the inputs of the summing block harmonic corrector and serially coupled pseudo-random sequence generator and a shaping filter th correlator, characterized in that, in order to increase accuracy and reduce time correction on pri20 25 thirty A shifting pulse generator, a clock shift unit, a clock generator, an analog-digital converter, interface unit, a microprocessor, a matching unit are input to the side, while the output of the synchronization unit is connected to the output of the clock shift unit on the receiving side, the other input of which is connected to the shift pulse generator output , to the input of the pseudo-random sequence generator, the output of the shaping filter is connected via a serially connected correlator, analog-to-digital converter, interface block, micro the processor and matching unit to the second inputs (n + 1) of discrete regulators of diversion coefficients of the harmonic corrector, the output of the summing block of which is connected to another input of the correlator, the output of the clock generator is connected to other inputs of the analog-digital converter and the microprocessor, the other outputs of which are connected to another input interface unit and another input matching unit.