Transmitter, receiver and record carrier in a digital transmission system

Claim 1

A transmitter for a digital transmission system for transmitting a signal representing a wideband signal via a transmission medium, said wideband signal being sampled at a given sampling frequency F s , said transmitter comprising: an input terminal for receiving the wideband signal; signal splitting means coupled to said input terminal for generating, in response to the wideband signal, a plurality of M narrow-band sub-signals at a decreased sampling frequency, said splitting means splitting up the wideband signal into consecutive sub-bands having band numbers m which increase with the frequency, where 1≦m≦M, a sub-signal being composed of consecutive signal blocks, each signal block comprising q samples; bit allocation means for generating bit allocation information indicating the quantity of bits by which the q samples of a signal block are represented in a sub-band; quantizing means having input means coupled to the signal splitting means and control input means coupled to said bit allocation means, said quantizing means quantizing the M sub-signals in blocks in response to the bit allocation information from the bit allocation means; means for converting the quantized sub-signals into another digital signal suitable to be transmitted via the transmission medium; and means for applying the another digital signal to the transmission medium; characterized in that the transmitter further comprises: signal processing means having an input coupled to the input terminal, an output and a control signal input; second signal splitting means having an input coupled to the output of the signal processing means for generating, in response to the processed digital signal of the signal processing means, a plurality of M sub signals at a decreased sampling frequency, said second signal splitting means splitting up the processed wideband signal into consecutive sub-bands having band numbers m which increase with the frequency, said bit allocation means being coupled to said second signal splitting means for deriving the bit allocation information from the M sub-signals of the split up processed wideband signal, said signal processing means processing the wideband signal in dependence upon a signal processing control signal which is applied to the control signal input of the signal processing means.