Adaptive Antenna Grouping for Space-Time Block Coding and Spatial Multiplexing Hybrid System

This paper studies joint transmitter and receiver design for the space-time block coding and spatial multiplexing hybrid communication system with limited feedback. Existed QR group receiver uses QR decomposition of the channel matrix to separate the filtered versions of the multiplexed space-time coded symbol blocks followed by space-time decoder, and the performance of this scheme is usually limited due to diversity lack of the earliest detected block. To overcome this problem, in this paper each space-time data block adaptively selects the appropriate transmit antenna group according to channel state information. Furthermore, this transmit antenna grouping can be derived with low complexity using successive QR decomposition of channel matrix at the receiver, thus only the index of antenna grouping result in a predetermined codebook is needed to fed back to the transmitter. The performance of the proposed schemes is evaluated in correlated channels through computer simulations.