Blind recovery of MIMO QAM signals: A criterion with its convergence analysys

In this paper, The problem of blind recovery of QAM signals for Multiple-Input Multiple-Output (MIMO) communication systems is investigated. We propose a new criterion based on the real (or equivalently the imaginary) part of the equalizer outputs, with a cross correlation constraint. A performance analysis reveals the absence of any undesirable local stationary points, which ensures perfect recovery of all transmitted signals and global convergence of the algorithm. From the proposed criterion an adaptive algorithm is derived. It is shown that the proposed algorithm presents a lower computational complexity compared to the constant modulus algorithm (CMA) and multimodulus algorithm (MMA). The effectiveness of the proposed algorithm is illustrated by some numerical results.