Alcatel Espace

Chantal Lesthievent

Eric Belis

Claudine Flament

Patrick Oudart

A digital filter method comprising the following steps: input signal data x(n) is sampled at sampling frequency Fe and shared between and stored in Q memories of shift register of FIFO type associated with the Q branches of the filter. The filter coefficients g.sub.m (p) are stored in at least one other memory referred to as a 'coefficient' memory. Interpolation by L followed by decimation by M makes it possible to reduce the working frequency of the filter to the output frequency Fs=(L/M)Fe with L/M&lt;1. Data samples x(n) are multiplied by the coefficients g.sub.m (p) at the rate Fs. According to the invention, the data samples x(n) in each branch remain present for a plurality of multiplications .apprxeq.Fe/Q, and the coefficients are rotated in each branch by address permutation in the coefficient memory at each clock period. The invention proposes various devices implementing the method. Applications in radar and in telecommunications.

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Portet/Garonne, France

Chantal Lesthievent