Implementation of the logical predistortion method to reduce the intersymbol interference of digital signals

Abstract

Article is devoted to proposed method of intersymbol distortions eliminating of digital signals in wideband channels. Method is used in two side channels. Parameters of signals are controlled in every side of channel and this information is translated backwards to transmitter side. Parameters of transmitted signal are regulated according to this information. So far as in become known signal change after intersymbol interference after transmission through channel, so necessary alterations of translated signal may be done. Intersymbol interfererence change logical content of informational signal, because of it some predistortions are made not in physical signal but in its logical content. Informational sequence is changed so that after transmission through channel to be more correspond to transmitted sequence that to immutable sequence. Method of sequence transformation is proposed. Method is based on modified Viterby algorithm. Modification consists in change of calculation of various ways along trellis. Except the algorithm has to be used in transmitter and not in receiver. Use of proposed method gives possibility to decrease bit errors in digital signal transmission in channels with intersymbol interferences.