Alamouti proposed orthogonal STBCS for two transmit antennas with code rate one. Tarkoh investigated for three to eight transmit antennas with code rate 1/2. Jafarkhni proposed for non orthogonal STBCS four transmit antennas with code rate one. The theory of space-time block codes was further developed by Weifen Su and Xian-Gen Xia. They defined space time block codes in terms of orthogonal code matrices. The properties of these matrices ensure code rate of 7/11 and 3/5 for 5 and 6 transmit antennas. For five, six, seven and eight transmit antennas, four generalized complex orthogonal space-time block codes of code rate with 2/3, 2/3,5/8, and 5/8 proposed recently . This paper intends new matrix GCOD Space time block codes for five, six, seven transmit antennas which can send 8 information symbols in a block of 8 channels with code rate of 1.
Keywords: Complex orthogonal designs, decoding delay, MIMO technologies, space time block codes, transmit diversity, transmit antennas.