Error performance of circular 16-DAPSK in frequency-selective Rayleigh fading channels with diversity reception

An expression for the error probability of raised cosine filtered circular 16-ary differential amplitude and phase shift keying (circular 16-DAPSK) in a frequency-selective Rayleigh fading channel with postdetection diversity reception is obtained. The effect of delay spread, modulation ring ratio and filter roll-off are also considered in the formulation. For a constant bit rate, the average irreducible bit error probability for circular 16-DAPSK is shown to be superior to that of 16-DPSK but slightly worse than Q-DPSK.