Time-Robust MRC Design for Broadcasting Reception Enhancement

Timing mismatch among signals of different receiving antennas degrades the maximum ratio combining (MRC) performance in broadcasting systems, and thus limits the output signal-to-noise ratio (SNR) after MRC. To circumvent this limitation, in this paper, a time-robust MRC (TR-MRC) receiver for broadcasting reception enhancement is designed by employing the tapped-delay-line (TDL) structure, where the weight matrix is derived as iterated-form and the average output SNR is calculated as closed-form. Simulation results confirm that the proposed TR-MRC receiver can improve the average output SNR and reduce the bit error rate (BER) under imperfect time alignment, especially for large number of receiving antennas and high input SNR. However, blindly increasing the TDL order can not bring significant improvement of the TR-MRC performance with unknown timing mismatch, showing a trade-off between the output SNR and the implementation complexity introduced by increasing TDL order.