SU1075435A1 - Regenerator of binary linear signal - Google Patents

Abstract

A BINARY LINEAR SIGNAL REGENERATOR, containing an amplifier with a correction signal, a subtraction unit, the first input of which is connected to the input of a delay line whose output is connected to the second input of the subtracting unit, the output of which is connected to the element of the two-way rectifier element; and to the input of the time recovery unit, the output of which is connected to the second input of the coincidence element, the output of which is connected to the input of the first counting trigger, and the output an amplifier characterized by the fact that, in order to increase the noise immunity, a phase equalizer, a low-pass filter and a second counting trigger, whose clod is connected to the input of the output amplifier, are inserted, the output of the amplifier with a correction circuit through the series-connected low-pass filter and phase the equalizer is connected to the input of the delay line, and the output of the first (L counting trigger is connected to the input of the second counting trigger. with Vhb9 -dH fO

Description

The invention relates to telecommunications and can be used in digital transmission systems. A known regenerator of dipolar pulses contains an amplifier with automatic gain control, the output of which is connected to the first inputs of the first and second decision blocks and to the inputs of a block of the timing signal, the output of which is connected to the first inputs of the output matching blocks and to the second inputs of the first and second decanters blocks, the outputs of which are connected to the second inputs of the corresponding output matches of the blocks, the outputs of which are connected to the transformer 1. The disadvantage of this device - no noise immunity. The most technical solution to the invention is a binary linear signal generator containing an amplifier with a correction circuit, a subtraction unit, the first input of which is connected to the input of a delay line, the output of which is connected to the second input of the subtraction unit, the output of which is connected to the input of a full-wave rectifier l, the output of which is connected to the first input of the coincidence element and to the input of the time interval recovery block, the output of which is connected to the second input of the coincidence element, the output of which It is connected to the input of the first counting flip-flop, and vyhodnoe amplifier 2. However, the well-known regenerator has insufficient noise immunity due to the wide bandwidth of the transmission line of the linear signal. The purpose of the invention is to improve the noise immunity. To this end, a binary line signal regenerator containing an amplifier with a correction circuit subtracting the block, the first input of which is connected to the input of the delay line, the output of which is connected to the second input of the subtracting block, the output of which is connected to the input of a two-field periodical rectifier whose output connected to the first input of the match element and to the input of the recovery time block, the output of which is connected to the second input of the match element, the output of which is connected to the input of the first counting trigger, and the output amplifier is entered, the phase equalizer, the low-pass filter and the second count H fi trigger, the output of which is connected to the input of the output amplifier, and the output of the amplifier with a correction circuit through the series-connected low-pass filter and phase corrector is connected to the input of the delay line, and the output of the first the counting trigger is connected to the input of the second counting trigger. FIG. Figure 1 shows the structural electrical circuit of the proposed regenerator; in fig. 2 - time diagrams of his work. The proposed binary linear signal regenerator contains delay line 1, correction circuit amplifier 2, block 3 subtractions, full-wave rectifier 4, coincidence element 5, first counting trigger 6, output amplifier 7 ,. a time interval recovery block 8, a phase equalizer 9, a low-pass filter 10 and a second counting trigger 11. The regenerator / operates as follows. The binary linear signal CQ (Fig. 25) at the input of the input cable comes from a predetermined regenerator identical to the one proposed, i.e. The CQ signal is identical in shape to the output signal Cj (Fig. 2k) of the proposed regenerator, however, the signal Cd obviously is ahead of the signal Cf by an amount equal to the propagation time of the CQ signal in the input cable in total with the regeneration delay time of this signal. In Figure 2 $, the CQ signal for convenience is shown without taking into account its propagation time in the space: shifted to the right by an amount equal to the propagation time. The binary linear signal C is a two-level signal with levels that are symmetrical about the zero potential. For definiteness, we assume that an elementary nonzero supply of the signal Co is a positive pulse with a duration of one clock interval (Fig. 2a), counted from the lower level. The probability of a CQ signal is equal to the likelihood of a skip (no parcel). Such a signal is a pulsed random process with a deterministic clock interval. In the energy spectrum of such a signal, the constant component is absent, but the continuous part of the spectrum has a maximum at zero frequency and smoothly drops to zero in the frequency band from to, where FT is the clock frequency of the binary linear signal Cd. In the cable, the Co signal is attenuated and distorted due to the greater attenuation of the higher frequencies of its spectrum, however, the amplifier 2 with a correction circuit fully compensates for

amplitude-frequency distant sign. In the O – Pt / 2 frequency band, it amplifies the signal, and the Fourier spectrum of a single send of the Cg signal at the output of the amplifier 2 with the correction circuit has a constant value in this frequency band. The lowpass filter 10 suppresses all components of the signal spectrum as well as. bellows lying in frequency above f Ff / 2; the phase corrector 9 compensates for the total phase-frequency distortion of all previous links of the path (cable, amplifier 2 with the corrected loop and the low-pass filter 10), and the resulting phase-frequency characteristic 15 of the path has the form of a line passing through the origin. As a result of this single. sending a signal C} SFig. 2b) at the output of the phase corrector 9 (for example, 20 on the 2nd clock interval, FIG. 2a) has the form of a bell-shaped impulse with a base 2T duration (where is a binary linear signal interval), with a length of 25 by the level of 0.7 equal to T, and with a known amplitude (which is usually chosen in the range of 1 to 3 V).

Since, at the output of the previous zo-regenerator (as part of the output amplifier 7) and at the input of the proposed regenerator (as part of the amplifier 2 with a correcting circuit), there are trasformators, weakened at the lowest frequencies of the C signal spectrum, the series of identical packages in the signal C has a flat top recession (for example, at 4–8 clock intervals).

Such a signal Hfe is suitable for anaglysis, therefore the signal Cd is preliminarily subjected to additional processing in the subtractive unit 3/31 and 1 delay and full-wave rectifier 4.45

Subtractive unit 3 extracts the difference between the instantaneous values of the CQ signal, separated from each other by a time interval equal to two clock intervals of the binary linear signal, by subtracting the signal from the signal C (Fig. 2z) i. The same signal C, but delayed by a line of 1 delay per 2T, i.e.; on 2 clock intervals of a binary 55 linear signal. I.

As a result, the output of the subtracting unit 3 forms a three-level signal C (Fig. 2) with positive /, negative and zero- 60 left messages, in which long series of identical non-zero messages are corrupted, which means that the flat top of the sending series is eliminated j lok. More precisely, I can say that 5

In the signal, further orders (or separated by an arbitrary number of zeros) of more than Two non-zero powders of the same sign may follow. A non-zero sending of the signal C appears at each clock interval in which the change in the sending of the signal C has occurred compared with the sending of the same signal, which has been released 2 clock intervals earlier.

. After a full-wave rectification of the signal C in a two-selective period. The selector 4 produces a binary signal C4 (Fig. 2e), in which there are zero (with zero potential) and positive signals, and the positive premises are the result of the positive and negative premises of the signal Cj. The output of the full-wave rectifier 4 is galvanically connected to the first input of the element 5 coincidence so that the flat veraoins of the series of positive parcels in the signal Cd, arriving at the element 5, do not coincide. The second input of element 5, coinciding with the output of the block of 8 time intervals, receives a signal Cg (Fig. 2g), which is a sequence of narrow positive pulses (strobe pulses) with a frequency equal to the clock frequency F of the binary linear signal ,. and located in the middle of the clock intervals. The SL signal is formed in the time interval recovery block 8 from the C4 signal subjected to two-sided limitation and narrowband filtering. The coincidence element 5 at each clock interval analyzes the signal Cd by comparing its instantaneous value (potential) in the middle of the clock interval with a threshold level (response threshold of coincidence element 5) equal to half the amplitude of the signal C and outputs the narrow pulses of the signal Cj (Fig. 2j) for those clock interval 1X, at which the instantaneous value of signal C exceeds the response threshold of element 5 coincidence at the time of the appearance of the strobe signal Cg Thus, the two-wave rectifier 4 together with the element The coincidence unit 5 forms a solver, which makes a decision on the presence or absence of a non-zero reference in signal C.

The signal Cg controls the first counting trigger b with a counting input, causes it to change state (opposite) for each pulse of this trigger. The output signal C (Fig. 2i) of the first counting trigger 6 in turn controls the common counting trigger 11 with a counting input, causing it to change out (to the opposite) at each positive pulse of signal C. As a result, the output of the second counting trigger 11 generates a binary signal C (Fig. 2k), which repeats the shape of signal C, the inputs to the input of the incoming cable. Amplified by the output amplifier 7, the signal C from the regenerator output enters the outgoing box: 6-line (linlu) as signal C. Thus, the signal at the output of the regenerator repeats the signal at the input of the input cable, i.e. The regenerator provides for the regeneration of a linear signal distorted by a cable and distorted by a cable. It is important to emphasize that the Su signal at the regenerator output repeats the CQ signal at the input of the input cable only if the delay line 1 has a delay equal to 2 T, i.e. two clock intervals of a binary linear signal. With any other delays that are multiples of the clock interval (for example, with a delay equal to 1 clock interval), such restoration of the signal in the regenerator is not achieved. This is due to the fact that the conversion of the pre-loaded cable signal Co in the subtractive unit 3 is matched with its further transformations in the regenerator blocks (two-wave rectifier 4, element 5 coinciding with the counting trigger 6 and the second counting trigger 11) only when the line 1 is degraded delays equal to two clock intervals of a binary linear signal. When a signal propagates through a cable, interference (of thermal noise, transitional noise in the cable, external interference) is created (summed up) with noise that leads to the appearance of a circuit during signal regeneration. The accuracy of the error is determined by the relative signal / noise output from the output of block 3. A sufficiently large emission of interference can lead to a malfunction of coincidence element 5: skip ip on the ej-o output (if the interference reduces the amplitude of sending signal C, and hence signal C, to a value less than the threshold of element 5 coincidence) or the appearance of an extra pulse at its output (if the interference in the absence of a signal C, exceeds the threshold of element 5 coincidence). This in turn leads to the omission of the operation of the first counting trigger 6 or to its excessive triggering and, consequently, a change in the further operation of the second counting trigger c. After such an error, the output of the second counting flip-flop 11 (and the regenerator) will be a signal C, which differs from the signal C by the inversion of every second burst, i.e. A single error occurred multiple times in the linear signal Cj. In order to avoid such a multiplication of errors in the informational binary signal transmitted through the transmission path, this signal at the input of the path is converted into another binary signal, which is transmitted through the path as a binary linear signal. This transformation is carried out by two series-connected triggers with counting inputs. At the output of the path, the inverse transform of the transmitted signal is performed and the information binary signal is restored. This conversion is performed by a modulo-2 adder, which sums the transmitted linear signal received from the output of the last regenerator with the same signal delayed by 2 clock intervals of the linear signal. jB in this case, one pass erabatan. the first counting trigger 6 (or one extra flip of it) results in the omission of one non-zero send (or the appearance of one extra non-zero send) of the transmitted binary information signal. The accuracy of such an error in the information signal can be made quite small (on the order of K) when designing the regeneration section containing the cable and the regenerator, choosing the type and length of the cable and the parameters of the regenerator. Due to the narrower bandwidth of the regeneration section (compared to the known device twice), the proposed regenerator provides a higher signal-to-noise ratio than in the known device, i.e. The proposed regenerator has greater noise immunity while maintaining the speed of the binary linear signal-.

Fm.2

Claims (1)

BINARY LINEAR SIGNAL REGENERATOR, comprising an amplifier with a correcting circuit, a subtracting unit, the first input of which is connected; to the input of a delay line, the output of which is connected to the second input of the subtracting unit, the output of which is connected to the input of a half-wave rectifier, the output of which is connected to the first input of the element coincidence and to the input of the recovery unit time intervals, the output of which is connected to the second input of the coincidence element, the output of which is connected to the input of the first counting trigger, and the output force spruce, due to the fact that, in order to increase noise immunity, a phase corrector, a low-pass filter and a second counting trigger are inserted into it, the output of which is connected to the input of the output amplifier, the output of the amplifier with a correcting circuit through a low-pass filter connected in series and the phase corrector is connected to the input of the delay line, and the output of the first counting trigger is connected to the input of the second counting trigger. Figure 1