Bandwidth efficient OFDM transmitter diversity techniques

Space-time coded orthogonal frequency division multiplexing (OFDM) transmitter diversity techniques have been shown to provide efficient means of achieving near optimal diversity gain in frequency-selective fading channels. However, these known techniques all require a cyclic prefix to be added to the transmitted symbols, resulting in significant bandwidth expansion. In this paper, bandwidth efficient space-time and space-frequency block-coded OFDM transmitter diversity techniques are proposed that exploit spatial diversity to eliminate the need for a cyclic prefix.