A novel MIMO scheme based on code-index modulation and spatial modulation

Abstract

In this paper, a novel multiple-input multiple-output (MIMO) transmission scheme with high energy efficiency, high data rate and better error performance, called CIM-SM, is proposed by combining recently two promising modulation techniques, spatial modulation (SM) and code index modulation (CIM). In the CIM-SM scheme, the information bits are conveyed not only by the modulated symbols but also by the active antenna indices of SM as well as the spreading code indices. Thus, the proposed CIM-SM scheme spends less transmission power while performing faster data transmission compared with the conventional direct sequence spread spectrum (DS-SS), SM and CIM-SS systems. In addition, computer simulations have shown that CIM-SM scheme has better error performance than DS-SS, SM and CIM-SS systems during the symbol period. The performance analysis of the proposed system is performed over the Rayleigh fading channels for BPSK modulation.