General Expression for the Error Probability of Arbitrary Two-Dimensional Signaling with I/Q Amplitude and Phase Unbalances

The I/Q unbalance which is generated by a non-ideal component is an inevitable physical phenomenon and leads to performance degradation when we implement a practical two-dimensional (2-D) modulation system. This paper provides an exact and general expression involving the 2-D Gaussian Q-function for the SER/BER of arbitrary 2-D signaling with I/Q amplitude and phase unbalances over an additive white Gaussian noise (AWGN) channel by using the coordinate rotation and shifting technique. Through Monte Carlo simulations we verify our expression provided here for various 16-Quadrature Amplitude Modulation (QAM) circular constellations.