Patent ID: 6873954

Claim:
A method of improving speech quality in a communication system comprising a first terminal unit (TRX 1 ), which transmits speech signals having a first sampling frequency (F 1 ) and a second terminal (TRX 2 ), which receives the speech signals, the method performed at the second terminal and comprising: receiving said speech signals; decoding the received speech frame; buffering said decoded speech frame in a playout buffer of said second terminal (TRX 2 ); performing a dynamic sample rate conversion of said decoded speech frame comprising N samples on a sample by sample basis, said dynamic sample rate conversion comprising: creating a first LPC-residual excitation frame comprising N samples derived from said decoded speech frame; calculating whether a sample should be either added or removed from said first LPC-residual excitation frame; selecting, in response to a determination that said calculating so demands, the position where in said first LPC-residual excitation frame to add or remove a sample; generating a second modified LPC-residual excitation frame comprising at least one of N−1 and N+1 samples, in response to a determination that said calculating so demands; and synthesizing, in response to a determination that said calculating so demands, a second speech frame from said second modified LPC-residual excitation frame; and playing out, in response to a determination that said calculating so demands, said second speech frame from said play out buffer.