Space-time coding techniques for MIMO block fading channels with co-channel interference

In this paper, we consider the design of space-time codes for multi-input-multi-output systems operated in the presence of co-channel interference (CCI). In particular, we consider two different scenarios. In the first, the channel state information (CSI) is assumed to be known only at the receiver. Based on the pairwise probability of error analysis, we develop a new design criterion that determines the code robustness to co-channel interference (CCI diversity gain). We further develop an algebraic framework for constructing space-time codes that jointly optimize the fading and CCI diversity gains. The proposed framework is general for arbitrary numbers of transmit antennas and quadrature amplitude modulation (QAM) constellations. In the second scenario, we investigate adaptive space-time techniques that exploit partial CSI at the transmitter. Our proposed design combines appropriate transmit antenna selection with adaptive rate and power allocation to combat both multi-path fading and CCI.