Low complexity I/Q imbalance and channel estimation techniques for MIMO OFDM systems

In this paper, the joint estimation techniques of in-phase and quadrature-phase (I/Q) imbalance and channel impulse response (CIR) are proposed for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems over Rayleigh fading environments. A novel preamble-aided structure with orthogonal property is designed to cancel the image interference due to I/Q imbalance and channel effects. Simulation results confirm the proposed method with low computational complexity can accurately estimate the CIR and I/Q imbalance parameters and achieve better root mean square error (MSE) performance over RF impairment and multipath fading channel environments.