Intel Corporation
Efficient extension to viterbi decoder for TCM encoded and non-linear precoded inputs

Abstract:

A decoder circuit that supports non-linear precoded signals is disclosed. The decoder circuit comprises a modulo estimation circuit configured to receive a non-linear pre-coded quadrature amplitude modulated (QAM) data symbol and determine a modulo shift estimate associated with the received QAM data symbol, wherein the modulo shift estimate comprises a modulo shift that brings the received QAM symbol within the predetermined QAM constellation. The decoder circuit further comprises a QAM decoder circuit configured to map the received QAM data symbol to a winning constellation point, wherein the winning constellation point comprises a constellation point in an extended QAM constellation associated with the predetermined QAM constellation, and determine a quantized constellation point comprising a constellation point within the predetermined QAM constellation from the winning constellation point, based on applying the modulo shift corresponding to the modulo shift estimate to the winning constellation point.