The present invention relates to a decoder for use in a spread spectrum radio receiver which is capable of directly demodulating an L-length frequency-hopped, Q-level frequency shift keyed radio-frequency received signal into a baseband signal wherein a desired user's message signal is decoded into a...http://www.google.de/patents/US4392231?utm_source=gb-gplus-sharePatent US4392231 - Spread spectrum FH-MFSK decoder
