Improved echo cancellation over telephony networks exploiting synthetic chaos

An improved echo cancellation strategy is presented for telephony networks. The scheme exploits synthetic chaos to code the speech signal resulting in improved performance. The logistic map is utilised as the chaotic encoding mechanism where the bifurcation parameter is directly modulated by the speech signal. This is shown to result in whitening the speech PSD. Utilising 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 dB and -82.6 dB after 250 ms of uncoded and chaotic coded speech.