Performance analysis of Osman Nuri Ucan (ONU)-receiver for trellis coded M-QAM schemes in partial response channels

Abstract

In this paper, for the first time, trellis coded M-QAM modulated signals are analysed in partial response channels.The named Osman Nuri Ucan (ONU)-receiver is composed of an k-parallel unit memory decoder, k/k+1 rated systematic encoder, cascaded with PRS channel model. The combined trellis structure of the ONU-receiver reduces the state number from 2/sup k/2/sup nu /2/sup k+1/ resulting from k-unit memory of the parallel precoders. The nu unit memory of the systematic encoder and (k+1) unit memory of PRS channel model to only 2/sup k+ nu /. Therefore considering the PRS channel together with classical trellis coded M-QAM structures does not increase state number and decoding complexity. The ONU receiver improves both bandwidth efficiency and error performance while resulting in no increase in the decoding complexity. As an example, the error event lower bound of the ONU-receiver is derived for 4QAM-TCM having encoder memory nu =1 and nu =2 in AWGN and colored noise environments.