SIMULATION AND ANALYSIS OF THE DISTORTION GENERATED BY THE BULK-FFT DEMULTIPLEXER

This paper presents a method of evaluating the signal distortion intro duced by the mismatch between linear convolution in a finite impulse r esponse (FIR) filter and cyclic (circular) convolution in a frequency- domain filter. An example is given based on the application to a satel lite on-board multicarrier demodulator for the INTELSAT International Business Services (IBS) system. However, the techniques may be useful in many other applications where it is more convenient to implement a matched filter in the frequency, rather than the time domain, or vice versa. Results are presented based on both simulation and analysis, sh owing that a 25:50:25% overlap/save strategy is preferable to the conv entional 50:50% overlap/save.