Receiver design for MIMO-OFDM transmission over time variant channels

The paper considers a receiver design for space-time block coded MIMO-OFDM transmission over frequency selective time-variant channels. The receiver employs the expectation-maximization (EM) algorithm for joint channel and data recovery. It makes collective use of the data and channel constraints that characterize the communication problem. The data constraints include pilots, the finite alphabet constraint, and space-time block coding. The channel constraints include the finite delay spread and frequency and time correlation. The receiver employs an EM-based Kalman filter for channel estimation. The receiver is able to recover the channel (which varies from one space-time block to the next) and the data with no latency and to reduce the number of pilots needed. Simulations show that the receiver outperforms other least-squares based iterative receivers.