Abstract

In this paper, we analyzed the Semi-Blind approach channel estimation in MIMO-OFDM systems, and in\nparticular for LTE downlink. Proposed Semi-Blind approaches lead to significant improvements in the estimation accuracy,\nboth from an MSE and BER perspective, compared to the typical pilot based technique. However, exploiting the true discrete\ndistribution of the unknown symbols is computationally demanding, therefore we propose the use of two approximations on\nthe unknown symbols: the Gaussian and the Constant Modulus assumption to significantly improve the accuracy with respect\nto the pilot based approach, while reducing the computational overhead incurred when using true discrete distribution of the\nunknown symbols.