Two Stages Method for IQ Imbalance Compensation in Multi-FA OFDM System

In Multi-FA based OFDM system that processes multiple FAs in parallel, IQ imbalance components can be generated in several points, where we can largely classify IQ imbalance component occurring within single FA and IQ imbalance component occurring between multiple FAs. In order to compensate for performance degradation owing to IQ imbalance components in the Multi-FA OFDM system, we propose two stages method considering two IQ imbalance components in this paper. The first IQ imbalance component occurring within single FA is compensated by the IQ matching algorithm in time domain and the second IQ imbalance component occurring between multiple FAs is compensated by the IQ mismatching canceller in frequency domain. We propose frame structure in which the proposed algorithm is adopted and show the EVM performance on AWGN environment through link level simulation in which the IQ matcher only, the IQ canceller only and the IQ matcher and canceller are applied respectively.