Abstract: A demodulator to demodulate a complex signal formed by two carriers, in quadrature, the spectrum of which is spread by a pseudo-random signal, and which are modulated by an M-ary, Walsh, code comprises:a chain of registers to store 256 bits of a pseudo-random signal;a multiplexer to temporally multiplex the processing of the two carriers;a chain of correlation macro-cells having a systolic structure enabling temporal multiplexing and having intermediate outputs providing for partial correlation values on 16 chips;a device for the computation of linear combinations of the functions of partial correlation, to compute two functions of correlation corresponding to two carriers for each M-ary code;a demultiplexing and computation device to compute the module of the function of correlation for each of the Walsh codes which may modulate the signal to be demodulated;a device for the selection of the greatest value of the correlation functions and for the selection of the corresponding piece of data.