Tight Bounds and Accurate Approximations for the BER of DQPSK Transmission from Novel Bounds on the Marcum Q-Function

In this paper, we apply recently proposed bounds for the Marcum Q-function in order to derive novel tight bounds for the bit error rate (BER) in the case of differential quaternary phase shift keying (DQPSK) transmission, with Gray coding, over an additive white Gaussian noise (AWGN) channel. We then propose simple, yet very accurate, approximations for the BER. The computational complexity of the final approximate expression is significantly lower than that of the exact expression, but the entailed degradation is minimal. 1.