Patent ID: 8077636

Claim:
A transcoder for converting a first input signal to an output signal, the first input signal comprising a narrowband signal and the output signal comprising a wideband signal, the transcoder comprising: (a) a narrowband decoder for receiving the first input signal and outputting a decoded signal; (b) a first filter for receiving the decoded signal and outputting a first lower sub-band signal, the first filter having a transfer characteristic for introducing a first artificial aliasing into the decoded signal to produce the first lower sub-band signal; (c) a second filter for receiving the decoded signal and outputting a first upper sub-band signal, the second filter having a transfer characteristic for introducing a second artificial aliasing into the decoded signal to produce the first upper sub-band signal; and (d) a wideband encoder for receiving the first lower sub-band signal and the first upper sub-band signal, encoding the first lower sub-band and first upper sub-band signals, and producing the output signal; wherein the transcoder excludes an up-sampler and excludes a quadrature mirror filter.