Two novel rate-one fast-decodable space time block codes for four transmit antennas

This paper deals with two new rate-one, full-diversity space time block codes for four transmit antennas and one receive antenna. The proposed designs add extra symbol to the rate ¾ OSTBC for four transmit antennas with different strategies to make OSTBC rate-one and ensuring full-diversity. Also in this paper it is shown that the proposed STBCs are fast-decodable with QR decomposition. Simulation results show that proposed STBCs have better performance than other proposed designs. This idea is also proposed in [8] and [9] before, but in these works the authors do not consider larger signal constellation or do not optimize the coding gain.