METHOD AND APPARATUS FOR RANDOM FM NOISE CANCELLATION

摘要

A method for reducing noise caused by fading in FM radio systems . The algorithm described operates on a sequence of complex samples received at the input of the discriminator (501) from the output of the IF filter of a digitally implemented radio. After determination of magnitude (502), which yields the raw envelope of the received signal, the raw envelope information is processed via parallel paths to determine characteristics indicative of shape, amplitude and time of occurrence of noise pulses. The output signal from the discriminator (501) is processed (508) to determine noise pulse direction. A pulse generator (510) produces counter pulses based upon the previously determined characteristcs, and the counter pulses are combined (513) with the discriminator output to substantially cancel the noise pulses.