Adaptive Coding forWirelessSpread-Spectrum Communication Systems

Protocols foradapting therateofanerror-control codeindirect-sequence orfrequency-hop spread-spectrum packet radionetworks areevaluated forstatic channels andchannels withtime-varying parameters thataremodeledasfinite-state Markovchains. Theperformance ofourprotocols iscompared withtheperformance ofanideal protocol thathasperfect channel- state information andemploys a setofcapacity-achieving codes ofthesameratesasthecodesavailable toourprotocols. The statistics usedbyourprotocols foradaptation arederived from thedemodulator anddecoder inthereceiving radio, andtheyare provided tothetransmitting radio byafewbits thatareincluded ineachacknowledgment packet. Y(t)