BER Performance Analysis of Hybrid Carrier Framework with IQ Imbalance Compensation

In this paper, we investigate BER performances of hybrid carrier (HC) framework based on weighted-type fractional Fourier transform (WFRFT) precoding with transmitter (TX) in-phase/quadrature (IQ) imbalance. Orthogonal frequency division multiplexing (OFDM) and single carrier (SC) systems with IQ imbalance are unified in proposed HC framework. Considering IQ imbalance as interference, the signal-to-interference-plus-noise ratio (SINR) of HC scheme is calculated, and then theoretical BER expressions over fading channels with zero forcing (ZF) and minimum mean square error (MMSE) equalizers are derived. Since a performance gain is involved in SC scheme with IQ imbalance interference, SC BER is theoretically given as a special case. Furthermore, we also put forward an IQ imbalance compensation method for HC framework through removing IQ imbalance interference at the cost of enlarged noise. The postcompensation noise of HC scheme is calculated and used to derive analytical BER expressions. The compensation performances of HC with ZF and MMSE receivers are verified through theoretical and simulated results.