Performance Improvement of Coded Dual Hop Two Way Space Time Block Code Spatial Modulation

This paper presents two scenarios to improve the performance of Distributed Space Time Block Code Spatial Modulation (DSTBC-SM). The first scenario is achieved by using a simple XOR coding at sources and relays with simple decoding algorithm in relays and destinations sides. It is found that the system using X-OR with DSTBC and DSTBC-SM half encoding at the relay offers increased performance gain with low complexity. The second scenario uses turbo code to improve the performance of DSTBC-SM, where encoding is performed in sources, while relays detect received signal without decoding. Iterative turbo decoder is done in destination to reduce complexity of overall system. The simulation results have shown that the cooperative transmission with coded DSTBC-SM can achieve BER of 10-4 at a level of energy per bit of about 14 dB which is lower level than the cooperative transmission uncoded DSTBC-SM