Speech communication unit and method for error mitigation of speech frames

摘要

A speech communication unit comprises a speech encoder capable of representing an input speech signal, e.g. from microphone 202. The speech encoder is coupled to a main transmission path (281), for transmitting a number of speech frames to a speech decoder, and a virtual transmission path (282) for transmitting one or more references for a number of speech frames transmitted in the transmission path (281). The one or more references identify an alternative speech frame within the number of speech frames transmitted on the transmission path (281) to be used as a replacement frame when a frame is received including an error. A suitable alternative speech frame is one that exhibits a similar characteristic to the frame to be replaced, based on evaluation of a minimum weighted error. The speech communication unit provides the advantage that a more accurate replacement frame mechanism is provided, thereby reducing the risk of undesirable artefacts being audible in recovered speech frames.