Performance analysis of the MVDR channel estimator for space-frequency block coded MC-CDMA systems

Minimum variance distortionless response (MVDR)-type blind channel estimation algorithms for the downlink of space-frequency block coded multi-carrier code division multiple access (SFBC-MC-CDMA) schemes are developed and analyzed. The performance of the channel estimator under sufficiently large data record size and small noise assumptions is studied by deriving analytical expressions for the bias and the variance of the estimator. Analysis of the mean-squared error (MSE) of the proposed estimator shows that at sufficiently high SNRs the squared norm of the bias can be considered negligible compared to the variance of the estimator. Furthermore, we establish a bound on the MSE of the biased estimates which is specifically derived for downlink transmissions where the knowledge of only the spreading code of the desired user is available. Finally, simulation examples illustrate the performance of the MVDR channel estimator and the accuracy of our analytical results