A Multilayer Space-Time-Frequency Coding Scheme for MIMO-OFDM

We present a multilayer space-time-frequency (STF) coding scheme for wideband multiple-input multiple-output (MIMO) systems employing orthogonal frequency-division multiplexing (OFDM). With multiple receive antennas, we employ an iterative demodulator consisting of a low-complexity multilayer detector and a simple soft extrinsic combiner. The system performance is optimized by efficient power allocation among layers, as well as interleaver design and extrinsic scaling to reduce the extrinsic correlation. Simulation results demonstrate that the proposed multilayer STF coding scheme performs close to or even better than the optimized linear dispersion (LD) STF codes with maximum likelihood (ML) decoding. Unlike the existing STF codes, which need to be designed for different system configurations and channel statistics, the proposed multilayer STF strategy is a universal scheme that exhibit excellent performance under various conditions.