the combined benefits of decision feedback equalization and error correction coding are realized in a communications system by the use of a plurality of coders and decoders respectively disposed in the transmitter and receiver . the plurality of encoders and decoders is used to interleave the data symbols so that each coder and decoder is operative upon every mth symbol , where m is the number of coders or decoders . by a judicious choice of m , both the probability of noise impairing the recovery of successive symbols and the error propagation effects inherent in decision feedback equalizers are reduced .