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.

Abstract: A modem circuit associated with a communication system is disclosed. The modem circuit comprises a symbol tracking circuit configured to track a symbol timing associated with a downstream (DS) channel associated with the modem circuit, in accordance with a timing offset estimate. In some embodiments, the timing offset estimate comprises a unified timing offset derived based on one or more external channels associated with the modem circuit that is different from the DS channel. The symbol tracking circuit is further configured to apply a sample rate correction to a DS signal associated with the DS channel, based on the timing offset estimate comprising the unified timing offset, and apply a frequency correction to the DS signal, based on a frequency offset estimate comprising a unified frequency offset derived based on the one or more external channels.

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.