Repeated decoding and encoding in subband encoder/decoders

Control signal generator means for deriving a control signal from a wideband digital signal, that can be used in an apparatus as claimed in anyone of the preceding claims, comprising

• input means for receiving the wideband digital signal,
• splitter means for splitting the wideband digital signal into a number of M sub signals,
• output means for supplying the control signal,
• characterized in that further comprises delay means for supplying a number of delayed versions of the wideband digital signal,
• signal power estimation means for estimating the signal power in at least one of the M sub signals so as to obtain a power value for each of said number of delayed versions of the wideband digital signal, comparison means for comparing the power values for said number of delayed versions of the wideband digital signal and for detecting whether one of the power values is substantially smaller than another power value, the control signal generator means being adapted to generate a control signal upon such detection.

Control signal generator means for deriving a control signal from a wideband digital signal, that can be used in an apparatus as claimed in anyone of the preceding claims, comprising

• input means for receiving the wideband digital signal,
• splitter means for splitting the wideband digital signal into a number of M sub signals,
• output means for supplying the control signal,
• characterized in that further comprises delay means for supplying a number of delayed versions of the wideband digital signal,
• signal power estimation means for estimating the signal power in each of the M sub signals, and power combining means for combining the M signal powers of the M sub signals so as to obtain a combined power value for each of said number of delayed versions of the wideband digital signal, comparison means for comparing the combined power values for said number of delayed versions of the wideband digital signal and for detecting whether one of the combined power values is substantially smaller than another combined power value, the control signal generator means being adapted to generate a control signal upon such detection.

Apparatus for decoding M sub signals so as to obtain a wideband digital signal, the apparatus comprising

• input means for receiving the M sub signals,
• synthesis filter means for combining the M sub signals into said wideband digital signal, M being an integer larger than one,
• output means for supplying the wideband digital signal,
• characterized in that the apparatus further comprises delay means coupled between the synthesis filter means and the output means, for realizing a specific delay of the wideband digital signal.

Method of encoding a wideband digital signal, the method comprising the steps of

• inputting the wideband digital signal,
• splitting the wideband digital signal into a number of M sub signals, M being an integer larger than one,
• assembling digital information including said sub signals into a digital output signal having a format suitable for transmission or storage,
• characterized in that the method further comprises the step of delaying for realizing a specific delay of the wideband digital signal, prior to splitting the wideband digital signal.

Method of decoding M sub signals so as to obtain a wideband digital signal, the method comprising the steps of

• receiving the M sub signals,
• combining the M sub signals into said wideband digital signal, M being an integer larger than one,
• supplying the wideband digital signal,
• characterized in that the method further comprises the step of delaying for realizing a specific delay of the wideband digital signal.