Estimation and Compensation of IQ Imbalance for Both Transmitter and Receiver in WiMAX Systems

WiMAX systems are very popular in wireless communication now-a-days. The main reason behind its popularity is high data rates possible in WiMAX systems. But due to in-phase quadrature imbalance (i.e. IQ imbalance) at the transmitter (Tx) and receiver (Rx), the system performance may be degraded in WiMAX systems. Therefore, it is necessary to compensate for the in-phase quadrature imbalance. In this paper, we have studied estimation and compensation of IQ imbalance in transmitter as well as receiver. We haveformulated an efficient least square technique for estimating IQ imbalance parameters for WiMAX system.We have analyzed the BER performance of the WiMAX system using different methods of constellation modulation for e.g. QPSK and 16QAM using proposed method of estimation. Results clearly showed that the proposed least square technique for IQ imbalance have better performance. Keywords–In-phase quadrature imbalance (IQI), Worldwide Interoperability for Microwave access (WiMAX), Least square estimation (LSE), Bit error rate (BER), signal to noise ratio (SNR).