Influence and suppression of phase noise in multi-antenna OFDM

The influence of phase noise (PN) on the performance of a multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) based communication system is analyzed. As part of this analysis, an estimator for the common phase error (CPE) is derived, based on the maximum likelihood estimation (MLE), which was chosen for its asymptotic optimality. Since the computational complexity of the MLE procedure clearly rules out a cost effective solution, a reduced-complexity algorithm. based on least squares estimation (LSE) is designed which yields suboptimal performance. Simulation results reveal that the difference in bit-error-rate performance between systems applying the LSE or MLE of the CPE is very small. This implies that the LSE is well applicable for 802.11a based MIMO systems.