Time domain IQ imbalance compensation for wideband wireless systems

A time domain IQ compensation approach is proposed for wideband application where the IQ imbalance is frequency dependent. The proposed approach relies on known signal such as preamble in orthogonal frequency-division multiplexing (OFDM) signal data frame and radar echoes. Signal correlation property is used for noise elimination and signal frequency spectrum is divided into several sub-bands to deal with frequency-dependent IQ imbalance in wideband scenarios. In order to solve the number of computation increase problem caused by frequency spectrum sub-bands division, complementary code sequences are applied for calculation simplification by exploiting the uncorrelated properties between complementary code matrixes. By comparison with traditional time domain compensation method, the proposed approach exhibits better performance in low signal-to-noise ratio (SNR) and wideband scenarios.