Antenna Selection Techniques for Digital Relaying based Cooperative MIMO Channels
AbstractIn this paper, performance of joint transmit and receive antenna selection in cooperative MIMO channels is investigated over Rayleigh fading environments. A cooperative MIMO communication scenario in which all of the terminals are equipped with multiple antennas is considered where source want to transmit data to the destination with the help of the relay. The techniques developed in literature to combat error propagation effect in digital relaying networks such as cooperative maximal ratio combining (C-MRC), virtual noise (VN) based detection and selective relaying (SR) are exploited in this study to obtain new antenna selection criteria for cooperative MIMO systems. Only one antenna is selected and activated at each of the three terminals in a manner to minimize the end-to-end bit error rate (BER) of the overall system. This approach eliminates the requirement of space-time signaling in system design and reduces the complexity and cost by minimizing the number of the required RF chains in the network. Unlike most of the studies in the literature, we assume that the direct link between source and destination exists. Numerical results have shown that a diversity order of (nS + nR) * nD can be achieved for VN and SR based transmissions where nS, nR, and nD are the total number of the antennas at the source, relay and destination, respectively. Among the considered schemes, the best performance is obtained in case of SR based system model.