Complex Orthogonal Space-Time Block Codes Rates 5/13 and 6/14 for 5 and 6 Transmit Antennas

Space -time block codes from orthogonal design have two advantages, namely, fast maximum - likelihood (ML) decoding and full diversity. Rate 1 real space -time codes (real orthogonal design) for multiple transmit antennas have been constructed from the real Hurwitz - Radon families, which also provides the rate ¿ complex space -time codes(complex orthogonal designs) for any number of transmit antennas. Rate ¿ complex orthogonal designs (space - time codes) for three and four transmit antennas have existed in the literature. In this correspondence, we present generalized complex orthogonal designs rate for five and six transmit antennas with 5/13 and rate 6/14 respectively.