Abstract: In the receive subsystem, the analogue-to-digital converter (40) works on the output of the low-noise amplifier (33), at a chosen rate (F), which corresponds to a bandwidth sampling. The processing stages comprise a custom circuit (5), with * an input memory (510) arranged to contain N successive digital samples, renewed at the chosen rate in blocks of M samples, * a complex digital low-pass filtering function (511, 512), of chosen cut-off frequency, operating on the input memory to supply N filtered digital samples (515), * an M-periodic summing function (531) on the N filtered digital samples, supplying M filtered and summed digital samples (533), * an M?M discrete Fourier transform stage (55), operating on these M filtered and summed digital samples, the digital signals on the M outputs (559) of the Fourier transform representing M separate channels, of width defined by the cut-off frequency of the abovementioned low-pass filter.

Abstract: In the receive subsystem, the analogue-to-digital converter (40) works on the output of the low-noise amplifier (33), at a chosen rate (F), which corresponds to a bandwidth sampling. The processing stages comprise a custom circuit (5) with * an input memory (510) arranged to contain N successive digital samples, renewed at the chosen rate in blocks of M samples, * a complex digital low-pass filtering function (511, 512), of chosen cut-off frequency, operating on the input memory to supply N filtered digital samples, * an M-periodic summing function (531) on the N filtered digital samples, supplying M filtered and summed digital samples (533), * an M1M discrete Fourier transform stage (55), operating on these M filtered and summed digital samples, the digital signals on the M outputs (559) of the Fourier transform representing M separate channels, of width defined by the cut-off frequency of the abovementioned low-pass filter.