Tight bounds on the bit-error probabilities of 2DPSK and 4DPSK in nonselective Rician fading

The bit-error probabilities (BEPs) of matched-filtered differentially detected two differential phase-shift keying (2DPSK) and 4DPSK over the nonselective Rician-fading channel are studied using the upper bound in Kam (1994). The bound coincides with the exact error probability result in the binary case and provides very accurate estimates of the BEP in the quadriphase case, especially for high signal-to-noise ratio (SNR) and small K-factor. The bound provides a simple analytical handle for studying the behavior of the error probability as a function of the Doppler spectrum, the Doppler bandwidth, and the K-factor. A new result is obtained for the irreducible error-rate floor. The results are useful for the design of digital mobile radio communication systems