Patent ID: 7151802

Claim:
A decoder for producing a synthesized wideband signal, comprising: a) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; b) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; c) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; d) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; e) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and f) a high-frequency content recovering device comprising: i) a random noise generator for producing a noise sequence having a given spectrum; ii) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and iii) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal.