Soft-limiter RAKE receivers for coded DS/DPSK systems over pulse jammed multipath-fading channels

Two soft-limiter RAKE receivers are evaluated for coded direct-sequence/differential phase shift keying (DS/DPSK) signaling over a pulse jammed multipath-fading channel that use a combination of antenna and multipath diversity. One uses predetection selective (antenna) combining followed by postdetection equal gain (multipath) combining, and the other uses postdetection equal gain combining only. In either case, the postdetection diversity combiner output is soft-limited prior to decoding. It is shown that for increasing levels of diversity the soft-limiter becomes quite effective, resulting in a receiver performance that approaches a maximum likelihood (ML) soft decision receiver with perfect jammer state information.