A New Decision Feedback Compensation Technique of Carrier Frequency Offset and IQ Imbalance in Wireless OFDM Systems

This report presents a new compensation method for IQ imbalance and carrier frequency offset in wireless OFDM systems. In a RF circuit, a direct-conversion architecture has the advantage of reducing cost in receivers. However, this architecture induces the huge IQ imbalance and leads to the large degradation in demodulation performance. The proposed method estimates the residual IQ imbalance by using demodulated information and re-modifies the received signals. It has good performance to remove the imbalance and the carrier frequency offset. The simulation result has shown that the proposed method has about 2 dB improvement at BER = 10^-3, compared with the conventional method