Broad-band digital filtering method and a filter implementing the method

摘要

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 gm(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<1. Data samples x(n) are multiplied by the coefficients gm(p) at the rate Fs. According to the invention, the data samples x(n) in each branch remain present for a plurality of multiplications APPROX 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.