EM-Based Receiver Design for Uplink MIMO-OFDMA Systems
In this paper we propose an iterative receiver for uplink MIMO-OFDMA systems based on the expectation maximization (EM) algorithm. Iterating between the E-step and the M-step, the EM-based receiver updates the channel estimates and, refines data detection by increasing the likelihood function. Practical implementation issues are also considered: space-time block-coding (STBC) is incorporated to improve system performance against fading; a reduced-complexity algorithm is proposed, which simplifies the computation whilst not compromising performance.