A novel Spatially-Modulated Orthogonal Space-Time Block Code for 4 transmit antennas

This paper presents a novel Spatially Modulated Orthogonal Space-Time Block Coding (SM-OSTBC) scheme for 4 transmit antennas based on the concept of Spatial Constellation (SC) first proposed in [1]. In the scheme, transmit SM-OSTBC codewords are generated simply by multiplying SC codewords with OSTBC codewords. An optimization technique for the SM-OSTBC scheme to achieve a transmit diversity order of 3 is discussed. In addition, a simple maximum-likelihood (ML) decoder is derived. BER performance of the proposed scheme is evaluated via computer simulation and theoretical upper bound. It is shown that the proposed scheme outperforms various existing MIMO transmission counterparts in a number of application scenarios.