Improvement of bit-error-rate in decision feedback equalizer by preventing decision-error propagation

A technique for reducing the influence of a phenomenon known as error propagation through the decision feedback equalizer is proposed. An error threshold may be defined to compare with the decision estimation error. If the estimation error is less than the threshold, an assumption is made that the DFE is functioning correctly; otherwise, the decision is classified as unreliable and replaced by a temporary decision. The temporary decision is chosen to prevent further, self-sustained incorrect decisions. The estimation error caused by adopting the temporary decision is used to determine the correct decision, which replaces the temporary decision. Statistical analysis indicates that the performance of the algorithm critically depends on the value of the first postcursor and the accompanying noise level.