RIS-Assisted Joint Transmitter-Receiver Space Shift Keying Design for Highly Flexible Wireless Communications

This paper presents a novel scheme for Reconfigurable Intelligent Surface assisted Joint Transmitter-Receiver Space Shift Keying (RIS-JTRSSK), which achieves a higher Spectral Efficiency (SE) and a more flexible transmission. In the proposed scheme, the incoming bits are divided into three groups, where the first group is used to determine the number of active antennas in the transmitter and the receiver, and the remaining two groups are used to respectively determine the transmit and receive antennas combinations. Moreover, we study the transmission design of RIS-JTRSSK scheme in both cases of perfect and imperfect channel state information. The theoretical Bit Error Rate (BER) of RIS-JTRSSK is also investigated and an antenna selection algorithm as well as a fast elimination algorithm are proposed to further improve the BER performance of RIS-JTRSSK and reduce complexity, respectively. Meanwhile, a low-complexity detector is designed as an alternative method to maximum likelihood detector for reducing detection complexity along with complexity analysis. Finally, RIS assisted flexible transmitter-receiver space shift keying scheme is proposed as flexible version that enables a richer set of application scenarios. We evaluate the BER performance of RIS-JTRSSK and compare it with that of large intelligent surface assisted spatial modulation. In addition, two benchmark schemes, namely Intelligent Reflecting Surface (IRS) assisted transceiver space shift keying and IRS assisted transceiver generalized space shift keying are used to demonstrate the system performance of our proposed scheme. The simulation results prove that our proposed schemes has good BER performance and can achieve higher SE with the same number of antennas.