Performance analysis of CIM-STSK system

Code-index modulation (CIM) uses the index of spreading code to convey information, which can be integrated with different kinds of MIMO systems to achieve higher throughput. This paper proposes a novel CIM-integrated space time shift keying scheme called CIM-STSK. The CIM-STSK system employs three types of resources to transmit information bits, which are Hadamard codes, dispersion matrix indexes and QAM constellation symbols. The mathematical expression of the bit error rate of the CIM-STSK system is derived, and the theoretical analysis is validated with Monte Carlo simulation results. Compared with the corresponding CIM-SS, STSK, CIM-SM, and CIM-QSM systems, CIM-STSK scheme can not only improve spectrum efficiency, but also achieve a better error performance.