Tight bounds on the BEPs of DQPSK and /spl pi//4-DQPSK over the nonselective Rician fading channel with narrowband IF filter reception

The bit error probability (BEP) performance of differential quaternary phase shift keying (DQPSK) and /spl pi//4-DQPSK over the nonselective Rician fading channel is analyzed with narrowband IF filter reception. While the exact BEPs can be obtained in terms of Marcum's Q-function whose computation requires complicated numerical integration, this paper emphasizes simple, tight, exponential upper bounds, from which the behavior of the BEPs as a function of the various system parameters such as the signal-to-noise ratio (SNR) and the Rician K-factor can be easily deduced. In addition to academic contribution, being an extension of the previous work of Kam and Zhong (see Proc. of IEEE GLOBECOM'95 p.61-5, 1995) dealing with matched filter reception, our results are also useful for practising engineers who are involved in the design of digital cellular mobile communication systems.