Joint estimation of the channel and I/Q imbalance for two-way relay networks

In this work, we consider amplify-and-forward two-way relay networks operating under the imperfect conditions of in-phase and quadrature-phase (I/Q) imbalance. We propose novel, efficient solutions for the problem of joint channel and I/Q imbalance estimation and the related problem of optimal pilot design. Three different estimation algorithms are developed. The first is the pilot-based maximum-likelihood (ML) estimator. The second is a...