Joint Estimation of Channel and I/Q Imbalance in OFDM/OQAM Systems

In this letter, we propose a preamble-based joint estimation of channel and I/Q imbalance in orthogonal frequency division multiplexing (OFDM) with offset quadrature amplitude modulation (OQAM) systems. To estimate the mixed effect of channel and I/Q imbalance in frequency domain, a preamble utilizing the staggered structure of OFDM/OQAM signal is designed, and the approximated Cramer-Rao bound (CRB) of the estimation is given. Then, a lower bound of the approximated CRB is used to derive an optimized pilot symbol. Finally, the satisfied performance of the proposed method is confirmed by simulations.

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