SU421137A1 - NONLINEAR AUTOMATIC DATA TRANSMISSION CORRECTOR - Google Patents

Description

one

The invention is intended for telecommunications, in particular for data transmission over long-distance communication channels.

The overwhelming amount of high-speed data transmission equipment produced is equipped with an automatic harmonic signal equalizer using linear alignment principles. Also known as irin cin build a nonlinear binary equalizer.

In a nonlinear corrector, a nonlinear limiting element is used in each of its branches, the depth and characteristic of which are selected but by some definite algorithm.

However, such a corrector does not allow to reduce the effects of intersymbol interference.

The aim of the invention is to reduce intersymbol interference fusion.

To do this, a second detector connected to the input of the analog delay line, two shift registers for N bits, a modulator connected to the memory unit, and an additional adder connected to the level regulator are introduced into the proposed offset. The input of the first shift register is connected to the output of the additional detector, the input of the second shift register - with the additional output of the main detector, the outputs of the registers

the shear is connected to the modulators; the outputs of the modulators are connected to the additional adder.

The block diagram of the proposed non-linear corrector shown in the drawing.

It contains a receive filter 1 that performs optimal filtering of the signal against the background of fluctuating noise, an amplifier with an AGC that maintains the required sustained signal level of the received signal, the delay line 3 per L, for example, an analogue adder 4 the main signal with a compensation signal, the main detector 5, the identifier of the 3rd sign of the polarity of the corrected signal, the additional detector 6, the definitive sign of the polarity of the signal before the correction, the shift registers 7 and 8 c / V resp Waters, a source of 9 reference compensating signal, a regulator of 10 levels and a sign of a reference signal, a device 11 for automatically adjusting a corrector, a block 12 of memory storing the values of echo signals in L lagging and .V leading points for a clock interval of the received signal, , change Jup; not a sign of the values stored in the memory block, depending on the influence of the influencing factor and the polarity, and the adder of 14 sigals of interference influence. Let us assume that the values of the echo signals in each of the N onshore and L points lagging by the clock interval are known in advance: ..., b-b, ..., bff. The interference effect of each parcel is different and depends on the type of information: i-Hi oA of the a-jv,., (I, H1, ..., a, and y) sequence and preference and N trailing nasal bottles (it is not expected that more distant packages are negligible). To determine the lag of the lagging currents, the additional detector 6 is used, and the shift register 7 is used to memorize them. The polarity / V of the advance signals is determined on the main detector 5 and recorded in the shift register 8. Thus, for each time point in the shift registers ( 7 and 8) are written so: Sgn, ..., Sgn ai, Sgn ci, ..., SP-P front ,. Each of the modulators 13 vyioli em biSgn a failure, -. Obviously, such a veimma modulator is simple, since its function includes either the translation of the Sigial b, -, if Sgn QI - 1, or its inversion, if Sgn a; -M. Pa output of the adder 14 and the signal is obtained. Г, ...- Sgn а, This signal is not connected to the regulator 10, which controls Ezelicin and the sign of the reference signal produced by the signal source 9. If the equalizer is turned on during the modulator, the AC signal can be used directly to eliminate intersymbol interference. Then, the source of the reference signal 9, the controller 10 and the adder 14 is eliminated, and the outputs of the modulators 13 are connected to the adder 4. The compensating signal is not affected by interference. The advantage of the proposed corrector is also the use of an analogue delay line of half the length, since it only needs information about the links of the neighboring parcels that can be recorded on the Discrete shift registers. The advantage is also the presence of only one regulator. The outputs of the detectors 5 and 6, connected to the shift registers 8 and 7, should produce signals corresponding to the polarities of the received bursts, regardless of whether absolute or relative modulation is used. If a multi-position signal is used, the shift registers 7 and 8 must be composite and be able to memorize all possible values of each of the locations. The automatic tuning device 11 is connected to the main detector 5 and to the unit of type 12 of us. It can be built according to any known principle, including the adaptive one. A non-linear automatic corrector of a data signal containing a reception filter whose output is via a serially connected amplifier with automatic gain control, a delay line per L parcels and an adder are connected to the input of the first detector, one of the outputs of which is through the node the settings of the corrector are connected to the input of the unit, and the source of the reference signal, the output of which is connected to the input of the adder via the level and sign regulator of the reference signal, characterized in that, in order to reduce the effect of intersymbol interference, a second detector, shift registers by L bits, 2 L modulators are introduced into it, while the input of the second detector connected to the first shift register on N bits, and the output of the second shift register on the / V bits is connected to another output of the first detector, and the outputs of the memory unit are connected to the inputs of the adder through the corresponding modulators, to the other inputs of which are connected respectively the outputs of the first and second a shift register A for bits. HZh 3-