Full Euclidean Distance Based Selection Combining for SSK DF Cooperative Diversity Systems

Space Shift Keying (SSK) is a multiple-input multiple-output technique that has drawn more attention in recent years because of its low complex transceiver design. In this paper, an investigation on the Symbol Error Probability (SEP) performance of SSK in a Decode-and-Forward (DF) cooperative relaying system is done. The DF cooperative relaying scenario considers an origin node, an intermediate node and an end node with a direct link between origin and end node, and an indirect link between origin to the intermediate node and intermediate to end node. The SSK modulation is considered at the origin and intermediate nodes with Full Euclidean Distance based Selection Combining (FED-SC) employed at the end node for SSK symbol detection. The SEP expression of the SSK FED-SC in the DF cooperative relaying scheme is derived using the Order Statistics Approach (OSA). Further, a closed-form SEP expression is obtained using a Combined Order Statistics Approach (COSA) considering the number of receive antennas at the intermediate node is equal to the number of receive antennas at the end node. In addition, the closed-form asymptotic SEP expression is presented to evaluate the diversity order of the system. The SEP expressions derived through OSA and COSA are verified using the Monte Carlo simulations. The simulation results revealed that the proposed SSK FED-SC outperforms all the existing SSK DF cooperative selection combining schemes.