Joint Estimation of IQ Parameters and Channel Response for OFDM Systems
In this paper, the authors develop a new algorithm to jointly estimate the channel impulse response and Inphase-Quadrature (IQ) imbalances for OFDM systems. The estimation algorithm is based on the Expectation Maximization (EM) algorithm, exploiting information from the pilot symbols and detected data symbols in a systematic fashion. To reduce the complexity of the estimation algorithm, a suboptimal scheme is also introduced. The results indicate that the proposed algorithms achieve a significant improvement in the Bit Error Rate (BER) performance when compared with conventional data-aided algorithms.