Department of Electrical and Electronics Engineering2024-11-0920190018-954510.1109/TVT.2019.29302852-s2.0-85077494196https://hdl.handle.net/20.500.14288/410Spatial modulation (SM) sparse codemultiple access (SCMA) systems provide high spectral efficiency (SE) at the expense of using a high number of transmit antennas. To overcome this drawback, this paper proposes a novel SM-SCMA system operating in uplink transmission, referred to as rotational generalized SM-SCMA (RGSM-SCMA). For the proposed system, the following are introduced, first, transmitter design and its formulation, second, maximum likelihood and maximum a posteriori probability decoders, and finally, practical low-complexitymessage passing algorithm and its complexity analysis. Simulation results and complexity analysis showthat the proposed RGSM-SCMA system delivers the same SE with significant savings in the number of transmit antennas, at the expense of close bit error rate and a negligible increase in the decoding complexity, when compared with SM-SCMA.pdfEngineeringElectrical and electronicTelecommunicationsJournal Articlehttps://doi.org/10.1109/TVT.2019.2930285487191500086Q1NOIR01956