High sampling rate adaptive decision feedback equalizers

A parallel adaptive decision feedback equalizer (ADFE) architecture is proposed. It allows adaptation at every sample to effectively equalize intersymbol interference for applications that operate at high sampling rates and require fast tracking capability. It is shown that if the effect of error propagation is small, the filter coefficients of the parallel ADFE will be exactly the same as those of a serially adapting ADFE. Simulation confirms that the parallel ADFE effectively tracks a time-varying channel with typical signal-to-noise ratios at a sampling rate four times higher than that of a serial ADFE, while under the same channel condition a previously proposed block ADFE fails to converge and becomes unstable