An adaptive block decision feedback receiver for improved performance in channels with severe intersymbol interference

This paper describes an adaptive block decision feedback receiver for improved communication in difficult channels with severe, time varying intersymbol interference. The receiver extends a block decision feedback equalization (block-DFE) structure proposed by Williamson, Kennedy and Pulford in 1992. Their algorithm improved performance in examples of known channels with intersymbol interference. The new receiver uses an adaptive block-DFE structure which includes carrier recovery for fractionally spaced inputs. It significantly improves bit error rates in difficult unknown channels while reducing the number of adaptive coefficients compared to a similar adaptive DFE receiver. Performance curves of the adaptive block-DFE and adaptive DFE receivers are shown for several well-known example channels. It is also shown that this new structure requires significantly fewer adaptive coefficients than the DFE