Method for packet loss and/or frame erasure concealment in a voice communication system

摘要

A method for performing packet loss concealment (PLC) and/or frame erasure concealment (FEC) in a speech decoder of a voice communication system. In accordance with the method, if a segment of an encoded speech signal is determined to be bad, an excitation signal is derived by scaling a random sequence of samples, and long-term and short-term predictive parameters are derived based on parameters associated with a previously-decoded segment. The excitation signal is then filtered by a long-term synthesis filter and a short-term synthesis filter under the control of the respective long-term and short-term predictive parameters. If the number of consecutively-received bad segments exceeds a predetermined threshold, the decoded speech signal is gradually reduced.