An adaptive blind equalizer with signal separation for a MIMO system transmitting QAM signals

In this work we propose a multiple-input multiple-output (MIMO) equalization scheme which uses the CMA+AMA equalizer in a modified multi-stage approach that simultaneously recovers all signal sources. The CMA+AMA equalizer minimizes a linear combination of the constant modulus algorithm (CMA) and alphabet-matched algorithm (AMA) cost functions, and this has been shown to be an effective equalizer for recovering QAM signals in the SISO and SIMO environment. The MIMO equalizer applies individual multiple-input single-output (MISO) equalizers to the received data stream, which is modified during the update process, to simultaneously remove the recovered sources using a channel estimator. By measuring the mean square error (MSE) and symbol error rates (SER) for the recovered sources, we show the effectiveness of this new equalizer in recovering all sources transmitted by the MIMO system.