Space-Time Block Coding for Spatial Modulation
Space-time block coded spatial modulation (STBC-SM) which employs space-time block coding (STBC) for spatial modulation (SM) is proposed as a new multiple-input multiple-output (MIMO) transmission scheme. In the STBC-SM scheme the transmitted information symbols are expanded not only to the space and time domains but also to the spatial (antenna) domain therefore both core STBC and antenna indices carry information. A general framework is presented for the design of the STBC-SM scheme for any number of transmit antennas. The proposed scheme is optimized by deriving its diversity and coding gains to exploit the diversity advantage of STBC. A low-complexity maximum likelihood (ML) decoder is given for the new scheme. It is shown by computer simulations that STBC-SM provides approximately 3-5 dB (depending on the spectral efficiency) better error performance than SM and V-BLAST systems.