Joint Channel Estimation and SC-FDE Receiver Based on Stretch Factor Graph and Combined BP-MF Framework

Based on the hybrid message passing rule and partial Gaussian approximation (PGA) method, a novel multi-user interference elimination algorithm has been proposed in this paper, and is applied to the joint channel estimation and detection for MIMO-OFDM system. The “multiplication-summation” structure lies in the multi-user model makes the adoption of standard message passing rules difficult, since the performance and complexity cannot achieve simultaneously. The standard message passing rules include belief propagation (BP), expectation propagation (EP), mean field (MF), and the joint approaches as BP-MF or BP-EP. Based on the structure of multi-user interference, a hybrid message passing rule and partial Gaussian approximation based algorithm has been proposed in this paper, which can be seen as an amendment of the standard rule. By the evaluation of channel weight, the proposed method employ different message passing strategies to different users, thus compromise the complexity and performance. Simulation results shown that, the proposed MIMO-OFDM receiver approaching the best one in literature while has much lower complexity.