Multi-level Block-Coded Generalized Spatial Modulation

This paper presents a novel generalized spatial modulation (GSM) scheme with transmit diversity, termed multilevel block-coded generalized spatial modulation (MBC-GSM). Unlike space-time block-coded spatial modulation (STBC-SM) schemes that rely on space-time block coding (STBC), MBC-GSM integrates multi-level block-coded modulation (BCM) with a new class of antenna-index matrices to transmit index bits at higher coding rates. The proposed scheme achieves a transmit diversity order of two by designing antenna-index matrices with specific structural properties. For a given signal constellation, MBC-GSM offers higher spectral efficiency than STBC-SM. To support various complexity-performance trade-offs, three decoding algorithms are developed: maximum-likelihood Viterbi decoding, multi-stage Viterbi decoding, and a low-complexity decoding algorithm. Simulation results demonstrate that MBC-GSM achieves superior error performance compared to existing STBC-SM schemes with equal or higher spectral efficiency.