High-Rate Spatial Modulation Transmission Scheme With Block-Orthogonal Structure and Block-by-Block Sphere Decoding

The work in this paper is an extension of the recently proposed stacked Alamouti based spatial modulation (SA-SM) scheme. The motivation is that by taking advantage of the existing full-diversity full-rate (FDFR) space-time code, to construct SM transmission with the properties of higher spectral efficiency, non-vanishing determinants (NVD) property, as well as fast decoding. In the proposed scheme, we still use the stacked structure to construct the signal matrix, but Alamouti code in the SA-SM scheme is replaced by the FDFR Sezginer-Sari-Biglieri (SSB) code. The combination of stacked structure with SSB code can contribute to attaining the goals of our motivation. Since the proposed SM scheme has block-orthogonal (BO) property, we call it as BO-SM. We then present a low-complexity block-by-block sphere decoding for the BO-SM scheme owing to the variables corresponding to the same block are independent. Simulation results of bit error rate (BER) performance show that the proposed BO-SM scheme outperforms some newly presented diversity-achieving SM schemes.