High throughput concurrent lookahead adaptive decision feedback equaliser

A time-domain adaptive decision feedback equaliser (ADFE) for multi-gigabit wire-line 2-pulse amplitude modulation (PAM) communication systems is proposed. The throughput rate of a conventional ADFE is limited by the loops in the circuit. This investigation develops two methods for breaking or virtually breaking these loops. The first is the method of batch mode coefficient updating (BMCU), and the second is the concurrent lookahead (CLA) method. Since the loops are broken or virtually broken, a pipeline and/or a parallel method can be applied to design a throughput-rate-unlimited ADFE. The results of a simulation of the 10GBASE-S system reveal that the proposed BMCU-based CLA ADFE has the same average signal-to-noise ratio (SNR) as the original sequential ADFE for multi-mode fibres of length 30-90 m.