Low Complexity Recursive Channel Tracking Algorithms for MIMO-OFDM
MIMO-OFDM系统的低复杂度递推信道跟踪算法

Based on the Variational Bayes (VB) method, a novel low complexity semi-blind Bayesian iterative receiver with joint signal detection and channel tracking is proposed for MIMO-OFDM systems over time-varying multi-path channel. Using the VB Expectation-Maximization (VBEM) algorithm, a Recursive VBEM (RVBEM) channel tracking algorithm is derived for the newly proposed receiver. Since the RVBEM algorithm requires computation of matrix inversion, a Time domain and Frequency domain combined Low Complexity RVBEM (TF-LCRVBEM) algorithm is further proposed to reduce complexity. It is demonstrated that the TF-LCRVBEM algorithm completely avoids matrix inversion and obtains linear complexity by making some reasonable approximations. The simulation results show that the proposed receiver not only outperforms the conventional receiver, but also can achieve near optimal performance.