1. Transmission system comprising a transmitter for transmitting an input signal to a receiver via a transmission channel, the transmitter comprising an encoder with an excitation sequence generator for generating a plurality of excitation sequences, selection means for selecting an excitation sequence from a plurality of excitation signals resulting in a minimum error between a synthetic signal derived from said excitation sequence, and a target signal derived from the input signal, the transmitter being arranged for transmitting a signal representing the selected excitation sequence to the receiver, the receiver comprises a decoder with an excitation sequence generator for deriving the selected excitation sequence from the signal representing the selected excitation sequence, and a synthesis filter for deriving a synthetic signal from the excitation sequence, characterised in that the encoder comprises an analysis filter for deriving from the input signal a residual sequence, in that the encoder comprising excitation sequence selection means for selecting from a larger set of excitation sequences the plurality of excitation sequences having the largest resemblance with the residual sequence.