GAIN-SMOOTHING AMPLIFIER DEVICE AND METHOD IN CODECS FOR WIDEBAND SPEECH AND AUDIO SIGNALS

摘要

A gain smoothing amplifier device and method for modyfing the amplitudeof an innovative codevector in relation to a background noise signal presentin a previously sampled wideband signal. The gain smoothing amplifierdevice comprises a gain smoothing calculator for calculating a smoothedgain in response to a set of linear prediction filter coefficients, a factorrepresentative of voicing in the sampled wideband signal, a factorrepresentative of stability of the set of linear prediction coefficients, andaninnovative codebook gain. The gain smoothing amplifier device alsocomprises an amplifier for amplifying the innovative codevector in relation tothe smoothed gain to thereby produce a gain smoothed innovativecodevector. The gain smoothing amplifier device improves the perceivedsynthesized signal when background noise is present in the sampledwideband signal.