Robust Impulse Response Shortening for Discrete Multitone Transceivers

Channel shortening filter, also known as time domain equalizer (TEQ), is generally used to reduce the effective length of a long multipath channel. This has the potential to reduce the cyclic prefix in a multitone based communication system such as asymmetric digital subscriber line (ADSL). The performance of a TEQ could however degrade considerably in the presence of channel estimation error, and we provide a robust channel shortening filter design incorporating worst case error scenario. We looked at channel estimation error in the presence of Gaussian and impulsive noise, and demonstrated superior performance of the proposed robust scheme.