A transmit antenna selection scheme for STBC MIMO OFDM systems with imperfect channel knowledge

In this paper, an adaptive MIMO-OFDM transmitter with imperfect CSI is proposed to reach a maximum transmission rate under a given required bit error rate (BER) and a total transmit power constraints. This transmitter uses the adaptive two-dimensional (2D) coder-beamformer derived in Zhou, S. and Giannakis, G. B., (2002) for each OFDM space-time coded subcarrier, and the greedy adaptive scheme in Hughes-Hartogs, D. (1989) to pursue power and bit loadings. The transmit antennas are selected according to the resultant subchannel Frobenius norm. Compared to the scheme using the whole number of available transmit antennas and despite a certain performance loss, the proposed reduced-complexity architecture provides a viable spectral efficiency.