Dynamic allocation of STBC for OFDM based on WSSUS channel model

In this paper we analyze the effect of the frequency selectivity and time variation of the wireless channel over space time block code (STBC)s in an orthogonal frequency division multiplexing (OFDM) system for a mobile user terminal (UT). In order to mitigate the influence of the channel variability, we propose a dynamic allocation over the time-frequency OFDM grid: a criterion for dynamic allocation direction is derived for a wide sense stationary-uncorrelated scattering (WSSUS) channel. The dynamic allocation is assisted by a feedback augmented only by one-bit. Results shows that mobile users can greatly improve bit error rate (BER) performance with dynamically allocated symbols. The symbol error probability (SEP) gain is analytically studied for the Alamouti code and computer simulations are provided for ITU vehicular channel model for a downlink (DL) connection in a IEEE802.16e system.