SU1177918A1 - Adaptive corrector of intersymbol interference - Google Patents

Abstract

: An ADAPTIVE INTERSHOOL INTERFERENCE CORRECTOR containing a multi-tier delay line consisting of (n-1) delay elements, n adjustable amplifiers, each of which consists of a multiplier and a gain change unit, whose input is the control input of the adjustable amplifier, and the output connected to the first input of the multiplier and is the first output. adjustable amplifier, the second input of the multiplier is the information input of the adjustable amplifier, and the output is the second output of the adjustable amplifier, regenerator, subtraction unit, n multipliers, n integrators, adder, whose inputs are connected to the second outputs of the adjustable amplifiers, the output is connected to the first input of the subtraction unit, and through the regenerator - to the second input of the block; subtraction and is the output of the adaptive equalizer between / .d, symbolic interference, whose input is the input of the multi-link line that is connected to the input of the first adjustable amplifier and to the first input of the first multiplier, the outputs (p-1) of the delay elements are connected to the information inputs of the corresponding adjustable amplifiers and to the first inputs of the corresponding multipliers, the second inputs of the multipliers are combined and connected to the output of the subtraction unit, and the outputs are connected to the inputs of the respective integrators, which is distinguished by the fact that, in order to improve the accuracy of the correction between (L symbolic interference, n additional transients were introduced into it). knives, n rectifiers, n switches, the outputs of which are connected to the control inputs of the respective controllable amplifiers, the first inputs are connected to the outputs of the corresponding -J integrators and the first inputs-i of the corresponding additional multipliers, the outputs of which are connected to the second inputs of the corresponding 1001 switches, the control inputs of which are combined with the second inputs of the respective additional multipliers and are connected to the inputs of the corresponding connectors whose inputs are connected to the first outputs of the respective adjustable amplifiers.

Description

1, 1 The device relates to telecommunications and is intended to correct the intersymbol interference of modulated signals transmitted by multi-position modulation methods. The purpose of the invention is to increase the accuracy of the intersymbol interference correction. FIG. Figure 1 shows a structural electrical circuit for the adaptive correlation of intersymbol interference; figure 2 - the same, adjustable amplifier. Adaptive intersymbol interference corrector contains a multi-link delay line 1 consisting of (p-1) delay elements 2, adder 3, n adjustable amplifiers 4, each of which consists of a block 5 for changing the gain, multiplier 6, n integrators 7, n multipliers 8, regenerator 9, subtraction unit 10, n additional multipliers 11, n rectifiers 12, n switches The device works as follows. The input signal is fed to the multi-tier delay line 1, as well as to the input of the first controlled force, body 4, and to the first input of the first multiplier 8. Through the delay elements 2 of the multi-link delay line 1, the signal goes to all other adjustable amplifiers 4, i.e. multipliers 6 and the first inputs of all the other multipliers 8. From the second outputs of all adjustable boosters 4, the signals go to the inputs of the sender 3, the output of which is the output of the equalizer. At the same time, a corrector control signal is generated. The signal from the output of the adder 3 is fed to the first input of the subtraction unit 10, the second input of which receives the signal from the output 2 of the regenerator 9. The output of the subtraction unit 10 is the difference between the signal and its evaluation, which goes to the second inputs of the multipliers 8. The result of the multiplication through the corresponding integrators 7 to the first inputs of the corresponding additional multipliers I 1. It should be said here that if the gain of the adjustable amplifier 4 is changed by an amount more dependent on the magnitude of the distortion than the RMS algorithm (implemented in the prototype), then the accuracy of the adjustment of the offset is improved. In this case, the direction of adjustment must be maintained. For this, it is necessary to allocate a module for changing the transmission coefficient of each adjustable amplifier 4. This operation is performed by rectifiers 12. Modules for changing the transmission coefficients of adjustable amplifiers 4 from the outputs of the corresponding rectifiers 12 are fed to the second inputs of the corresponding additional multipliers 11, in which the multiplication of the coefficient transmission of each adjustable amplifier 4. With a control signal. The obtained products are passed through the corresponding switches 13 to the control inputs of the respective adjustable amplifiers 4, and then to the corresponding blocks 5 of the change of the transmission coefficient. A situation may occur when the signal module at the output of the rectifier 12 is zero. In this case, a false suspension of the control of the adjustable amplifier may occur. To prevent this from happening, the switch 13, when there is a zero on its control input, connects the control input of the adjustable amplifier to the output of the integrator 7. In this case, the control of the equalizer is implemented as in a known device.

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Claims (1)

ADAPTIVE INTERCHANGE INTERFERENCE CORRECTOR, comprising a multi-link delay line, consisting of (η-l) delay elements, η adjustable amplifiers, each of which consists of a multiplier and a gain block, the input of which is a control input / adjustable amplifier, and the output is connected to the first The input of the multiplier is the first output. variable amplifier, the second input of the multiplier is the information input of the adjustable amplifier, and the output is the second output of the adjustable amplifier, the regenerator, the subtraction unit, η multipliers, η integrators, the adder, the inputs of which are connected to the second outputs of the adjustable amplifiers, the output is connected to the first input of the subtraction unit, and through the regenerator - to the second input of the subtraction unit and is the output of the adaptive corrector of intersymbol interference, the input of which is the input of the multi-link delay line, which the first is connected to the input of the first adjustable amplifier · and to the first input of the first multiplier, · the outputs (η-l) of the delay elements are connected to the information inputs of the respective adjustable amplifiers and to the first inputs of the corresponding multipliers, the second inputs of the multipliers are combined and connected to the output of the subtraction unit, and the outputs are connected to the inputs of the respective integrators, characterized in that, in order to improve the accuracy of the correction of intersymbol interference, η additional multipliers are introduced into it, η straighten lei, η switches, the outputs of which are connected to the control inputs of the respective adjustable amplifiers, the first inputs are connected to the outputs of the respective integrators and to the first inputs of the corresponding additional multipliers, the outputs of which are connected to the second inputs of the corresponding switches, the control inputs of which are combined with the second inputs of the corresponding additional multipliers and are connected to the outputs of the respective rectifiers, the inputs of which are connected to the first outputs of the respective controllers Rui amplifiers.