Patent ID: 8265940

Claim:
A method for artificial extension of bandwidth of speech signals, comprising: encoding by a process comprising: providing a wideband input speech signal, the wideband input speech signal having an extension band outside of non-extended band; determining signal components within the extension band of the wideband input speech signal, the signal components being required for bandwidth extension into the extension band of the wideband input speech signal; determining spectral envelopes of the signal components; determining temporal envelopes of the signal components, the temporal envelopes being determined independently of the spectral envelopes, without using the spectral envelopes as an input; and encoding information for the temporal envelopes and the spectral envelopes to produce encoded information for extending the bandwidth; and decoding the encoded information and reconstructing the temporal envelopes and the spectral envelopes from the encoded information to thereby produce an output speech signal with extended bandwidth, wherein decoding and reconstructing comprise: producing an excitation signal in a decoder from an input signal transmitted to the decoder; determining a first correction factor from decoded information of the temporal envelopes and from the excitation signal; in a first reconstruction, forming reconstructed temporal envelopes by multiplying the first correction factor with the excitation signal; filtering the reconstructed temporal envelopes to produce pulse responses while filtering; and in a second reconstruction, forming reconstructed spectral envelopes from the pulse responses and the reconstructed temporal envelopes.