High-Rate Complex Orthogonal Space-Time Block Codes for High Number of Transmit Antennas

Complex orthogonal designs of maximum possible rate of full, 3/4, and 3/4 have been presented for 2, 3, and 4 transmit antennas respectively. For 5 and 6 transmit antennas, two generalized complex orthogonal space-time block codes of rates 7/11 and 3/5 were proposed recently. In this paper, we propose three complex orthogonal space-time block codes whose rates are up to 2/3, 2/3, and 5/8 for 5, 6, and 7 transmit antennas, respectively. Simulation results are provided to demonstrate the significant performance gains made by the proposed space-time block codes.