Robust decision feedback equalizer scheme by using sphere-decoding detector

Abstract

The decision feedback equalizer (DFE) is an efficient scheme to suppress intersymbol interference (ISI) in various communication and magnetic recording systems. However, most DFE implementations suffer from the phenomenon of error propagation, which degrades its bit error rate (BER) performance. In this paper, We use sphere detector (SD) to achieve maximum likelihood (ML) detection and significantly reduce the system symbol error rate (SER). Simulations show that the proposed scheme with sphere detector decision feedback equalizer (SD-DFE) algorithm can efficiently reduce the SER. At SNR=28, the SER can be improved from 2.0 × 10-5 (Ideal DFE) to 1.8 × 10-6 (six-stage SD-DFE).