Subspace-based blind channel estimation for cyclic prefixed MIMO-OFDM systems using few received blocks

In this paper, two subspace (SS) based blind channel estimation methods for cyclic prefixing (CP) based multi-input and multi-output (MIMO) OFDM systems are proposed. The first one generalized a previously reported single-input and single-output (SISO) based method into the MIMO case. The second one is an extension to the first one by smartly introducing additional columns per received block in the channel matrix equation. These two SS methods require few received blocks to satisfy the persistency of excitation (POE) criterion and do not require the number of receive antennas to be greater than that of transmit antennas. Simulation results demonstrate the capability of the proposed methods to perform blind channel estimation using few received blocks. Compared to multiple existing SS methods, significant performance improvements of the proposed methods are observed given the same amount of available received data.