A digital audio broadcasting (DAB) system includes a radio-frequency (RF) receiver that develops a characterization signal representative of a respective mobile communications channel as a precursor to estimating a channel impulse response. The latter is used to set coefficients of an equalizer...http://www.google.de/patents/US5822368?utm_source=gb-gplus-sharePatent US5822368 - Developing a channel impulse response by using distortion
