A Simple Estimation Scheme for Joint Estimation of Carrier Frequency Offset and I/Q Imbalance

This paper proposes a simple algorithm for joint estimation of carrier frequency offset and I/Q imbalance. The reduced complexity algorithm is derived from a closed form solution of the carrier frequency offset and I/Q imbalance parameters given two identical training blocks. The proposed algorithm also uses the least squares algorithm to give accurate estimate in the presence of noise. It was shown that for as little as 10 samples each from two identical OFDM symbols, the proposed algorithm can produce accurate estimate of CFO and I/Q imbalance. While the target system is OFDM, the proposed algorithm applies to any system as long as two identical data blocks are received in the receiver. Simulation results show that performance of the proposed algorithm that uses only 10 samples for complexity reduction is only ldB below a system without CFO nor I/Q imbalance degradation.