Efficient training and data transmission for cooperative MIMO communications: Space–time coding approach

The communication performance can be restricted by inevitable training overhead for acquiring channel state information (CSI). A space–time code (STC)-based cooperative communication scheme is proposed to reduce the training overhead by employing a two-antenna relay node (RN) that broadcasts merely two orthogonal pilot sequences from the two antennas to a source node (SN) and a destination node (DN). The received signal-to-noise ratio, the achievable rate, and the bit error rate are mathematically analyzed, and numerical results confirm that the proposed STC-based relay system increases the achievable rate irrespective of the number of antennas at SN and DN.