A low power normalized-LMS decision feedback equalizer for a wireless packet modem

This paper presents a decision feedback equalizer (DFE) for a high-speed packet modem utilizing the normalized least mean squared (NLMS) tap update algorithm. The equalizer supports up to 43.2 Mbit/s uncoded data over a wireless channel with a 10% training preamble (48 Mbit/s with no training). In this work the rapid convergence of the NLMS algorithm is combined a technique for early termination of the tap training process to yield a low power DFE implementation. The low power techniques result in a 43% power reduction over a baseline design. Furthermore, low power synthesis techniques result in an additional 30% power savings on top of the algorithmic power savings.