NONCOHERENT DEMODULATION OF OPTIMAL TRELLIS CODED CP M-ARY FM

EXISTING DIGITAL RADIO SYSTEMS USE CONTINUOUS PHASE, FREQUENCY MODULATION TECHNIQUES WITH COHERENT DETECTION. THESE SYSTEMS MUST TRADE SPECTRAL EFFICIENCY FOR LOW BIT ERROR RATE AND IN CERTAIN APPLICATIONS SUCH AS SATELLITE AND MOBILE RADIO ARE SUBJECT TO DEGRADATION DUE TO FADING AND DOPPLER SHIFTS. WE PROPOSE TO INVESTIGATE THE USE OF TRELLIS CODING OF THE SIGNAL SPACE WITH CP-FM, USING NON-COHERENT, DISCRIMINATOR BASED DETECTION. THIS INNOVATIVE CODING SCHEME WILL BE APPLIED FOR BOTH SYMMETRICAL AND ASYMMETRICAL SIGNAL CONSTELLATIONS. WE WILLINVESTIGATE SYSTEM PERFORMANCE IN THE PRESENCE OF RICIAN FADING DOPPLER EFFECTS AND COMPARE OUR RESULTS WITH NON-COHERENT DETECTION OF STANDARD MODULATION SCHEMES (MSK, DUO-BINARY AND TFM). FINALLY, WE WILL SELECT, FOR A GIVEN CODE RATE N/(N+1), THE OPTIMUM MODULATION SCHEME. A SUCCESSFUL EFFORT WILL RESULT IN FAR MORE EFFICIENT COMMUNICATIONS SYSTEMS THAT REQUIRE LESS POWER FOR THE SAME BER; REDUCED WEIGHT; HIGHER RELIABILITY; IMPROVED SPECTRAL EFFICIENCY; BETTER DOPPLER AND FADING PERFORMANCE; AND LOWER COSTS.