Turbo ISI cancellation for recursive communication channels

A linear inter-symbol interference (ISI) canceller (LC) structure optimized in terms of complexity for generalized recursive channel applications with decaying exponential response is introduced. Taking advantage of recursive channel properties, proposed optimized LC replaces the ISI filter with a cascade of a much shorter linear filter and a single pole IIR named auxiliary fixed filter (AFF). The optimum solution for conventional and the new proposed LC is derived for generalized recursive channels. The new computationally efficient LC is used in turbo equalization and is shown to have equivalent or better performance than the conventional LC in terms of BER.