Coded space-time-frequency OFDM over IEEE 802.11 fading channels

Abstract

This paper will present a 4-transmit and 1-receive (4Tx:1Rx) antenna system of coded space-time-frequency in conjunction with orthogonal frequency division multiplexing (Coded STF-OFDM). STF block code is concatenated with channel coding namely convolutional code of rate 1/2 with length 5 to further combat channel impairment. The coded STF scheme is compared to ST-OFDM and SF-OFDM over IEEE 802.11 multipath channel at delay spread of 700 ns and 1 ms in outdoor environments. Results show that Coded STF-OFDM scheme outperforms other schemes by as much as 8 dB (against ST-OFDM) at 700 ns delay spread. The scheme also outperforms others at longer delay spread but is almost comparable to coded SF-OFDM.