One of the simplest ways of detecting binary FSK is to pass the signal
through two bandpass filters tuned to the two signalling frequencies and detect which has
the larger output averaged over a symbol period. This is in essence a non-coherent envelope detector for the equivalent two ASK streams
with a comparator at the output. Because it takes no account of the phase of the
respective symbols, this method, as expected from our discussions on ASK detection, will not perform as well as coherent FSK detection
systems. |
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