Joint Estimation and Compensation of IQ Imbalance and Carrier Frequency Offset in MB-OFDM UWB Receiver

Studying the influence of IQ imbalance and carrier frequency offset (CFO) on the system performance in multi-band orthogonal frequency division multiplexing ultra wideband (MB-OFDM UWB) receiver, a joint estimation and compensation method of IQ imbalance and CFO was proposed in time domain and frequency domain. First, three repeat preambles were used to estimate and compensate the CFO and IQ imbalance in time domain. Second, pilots of data unit were used to estimate and compensate the residual IQ imbalance in frequency domain. The simulation results show that the method can overcome the influence of IQ imbalance and CFO, when CFO is 40 PPM, IQ imbalance factor is g=1.1 and θ=10°, the IQ imbalance and CFO can be compensated. The design method is of high accuracy, and is suitable for long symbol MB-OFDM UWB system.