A semi-blind MIMO adaptive equalizer based on independent space constraint

This work presents a semi-blind independent space constrained flat channel equalization adaptive algorithm for a multiple input multiple output (MIMO) system. The proposed equalization method consists of two stages, namely the training stage, where a short training signal is employed, and a blind adaptation stage, where a blind adaptive algorithm is used to ensure that the demixing matrix is always a nonsingular matrix. In the first stage of equalization, orthogonal signals are transmitted in each transmit antenna. At the receiver, the training signal is used to evaluate channel's state information (CSI), which is then projected to independent spaces. The blind stage of adaptation, which is based on the independent space constraint, has a relatively low computational complexity in comparison to other blind adaptive algorithms. Simulation results that have been provided verify that the algorithm is stable, after initialization using training signal.