Quasi Orthogonal Space Time Block Codes(QOSTBCs) made space time sequences transmiting with full rate, however, this encodeing method losed partly diversity performance for lowering the orthogonality between antennas. In order to solve to this problem,a transmiting antenna selection scheme for QOSTBCs was proposed. The method was based on R QO STBC, by adaptively mapping the space time sequences of the QO STBC to the appropriate transmiting antennas depending on the channel condition.The proposed scheme could improve its transmiting diversity with limited feedback information. The performance of the scheme with various numbers of antennas selection patterns was also analyzed. The bit error probability of the schemes was evaluated by simulations. It was demonstrated that with the linear zero forcing (ZF) and the minimum mean squared error (MMSE) receivers, the closed loop QO STBC using two feedback bits can achieve almost the same performance as the ideal 4 path diversity and it is about 4~5 dB better than the open loop schemes.
