I/Q 위상 불균형을 고려한 Uniform M-PSK의 일반화된 BER 성능 분석

Abstract

본 논문에서는 2차원 결합 가우시안 Q-함수(Two-dimensional joint Gaussian Q-function)를 이용하여 AWGN (Additive White Gaussian Noise) 환경에서 M-PSK(M-ary Phase Shift Keying) 신호의 IQ 위상 불균형(Phass unbalance) 존재 시 수치 적분이 필요 없는 정확하고 일반화된 closed-forin 형태의 비트 오류율(Bit Emor Rate 10 & 1c) 표현을 유도한다.

1/Q phase unbalance caused by non-ideal circuit components is inevitable physical phenomenons and leads to performance degradation when we implement a practical coherent M-ary phase shift keying(M-PSK) demodulator In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate(BER) of uniform M-PSK with I/Q phase unbalance over an additive White Gaussian noise(AWGN channel. First we derive a BER expression for the k-th bit of 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and genera average BER expression for M-PSK with I/Q phase unbalance. This result can readily be applied to numerica evaluation for various cases of practical interest in an I/Q unbalanced M-PSK system, because the one and two dimensional Gaussian Q-functions can be easily and directly computed using commonly available mathematica software tools.