I. Introduction
Existence of perfect timing is assumed by many researchers for analyzing the performance of a communication system. However in practical communication systems there are often errors in timing which must be accounted for in performance analysis. An error in timing effects the probability of correct decisions at the receiver. The effect of timing error on the performance over an additive white Gaussian Noise (AWGN) channel has been studied in the literature. A closed form expression for the conditional BEP for differential phase shift keying (DPSK) modulation over an AWGN channel is presented in [1]. Bit-error-rate (BER) performance of generalized hierarchical phase shift keying (PSK) constellations under imperfect phase or timing synchronization over an AWGN channel is presented in [2].