Echo cancellation strategy using chaotic modulated speech

A novel speech coding strategy that can be used for telephony channels and that allows existing echo cancellers to approach their fundamental operating limit is reported. A chaotic-based modulation regime which uses logistic mapping is exploited to whiten the speech PSD. By using the described strategy, an echo attenuation of 50.3 dB was achieved after only 2000 iterations (250 ms) as opposed to the conventional 23.4 dB over the same interval. Furthermore, the model misadjustment was -17.8 and -82.6 dB after 250 ms of uncoded and chaotic coded speech, respectively