Performance Analysis of a Partially Coherent System Using Constellation Rotation and Coordinate Interleaving

The performance analysis of a system employing coordinate interleaving and constellation rotation, over Nakagami- m fading channels, in the presence of phase noise as well as additive white Gaussian noise (AWGN) is presented. The phase locked loop (PLL) dynamics result in phase noise thereby introducing imperfect receiver phase estimates which are assumed to have Tikhonov densities. The resulting performance degradation of the system due to the phase noise is analyzed and an upper bound for the average probability of bit error (Pt) for M-ary phase shift keying (MPSK) is presented. It is shown that in the presence of phase noise the optimum rotation angle does not change and that the upper bound is tight for high signal-to-noise ratios (SNR). Furthermore, we also show that a system employing coordinate interleaving and constellation rotation is more robust against phase estimation errors.