Improving Spatial Modulation performance in Distributed Antenna Systems

Having multiple-antennas distributed in a large area in Distributed Antennas Systems (DASs) results in performance improvement such as increased coverage and greater spatial diversity. Simulcasting, in which a message is transmitted over the same frequency band by all antennas simultaneously, is one of the main applications used in DAS. Orthogonal Space-Time Block Codes (OSTBCs) have been proposed for these systems. However, the rate decreases dramatically when there are more than two antennas in the system. Spatial Modulation (SM) is another method introduced for multiple-antenna systems to increase spectral efficiency. We analyze the performance of both STBC and SM in simulcasting DAS. Error probability relations are derived and verified for these schemes. We also propose a new STBC-SM code, a mixture of STBC and SM, to improve the performance of SM in DAS.