Pre- and post-processing for optimal noise reduction in cyclic prefix based channel equalizers

Cyclic prefix based equalizers are widely used for high-speed data transmission over frequency selective channels. Their use in conjunction with DFT filterbanks is especially attractive, given the low complexity of implementation. Some examples include the DFT-based DMT systems. We consider a general cyclic prefix based system for communication and show that the equalization performance can be improved by simple pre- and post-processing aimed at reducing the noise at the receiver. This processing is done independently of the ISI cancellation performed by the frequency domain equalizer.