An efficient low complexity clustering-based MLSE equalizer for frequency-selective fading channels

Recently, a sequence equalizer, the 1-D CBSE equalizer, which belongs to the family of Cluster-Based Sequence Equalizers and achieves the Maximum Likelihood solution to the equalization problem, was reported. The 1-D CBSE does not require the explicit estimation of the channel impulse response. Instead, it utilizes the estimates of the cluster centers formed by the received observations. In this paper, a novel cluster tracking scheme is presented which allows the application of the 1-D CBSE in time-varying transmission environments. Although the proposed equalizer exhibits similar performance with that of the classic MLSE-LMS equalizer, the overall required computational load is dramatically reduced. This is achieved because the new method provides the means for an efficient exploitation of the symmetries underlying the signaling scheme.