A Novel Low Complexity-Sparse Recovery Detector for Differential Space Shift Keying MIMO System

A novel low complexity sparse recovery (SR) detection algorithm for differential space shift keying (DSSK) multiple input multiple output (MIMO) system is proposed and analyzed in this letter. In DSSK system, channel knowledge is alleviated at the receiver, and the receiver relies on the received blocks at two consecutive time slots to decode the transmitted signal. Besides, DSSK facilitates the deployment of arbitrary number of transmit antennas not necessarily power of two, while retaining most inherent advantages of coherent SSK system, such as single RF-chain deployment. Yet, the receiver computational complexity of DSSK grows exponentially with the transmitted block size and optimum detection gets impractical for large configurations. The DSSK detection is formulated as a SR optimization and a new SR algorithm, called combined matching pursuit (CMP) is proposed. CMP utilizes the inherent sparsity of DSSK system and shown to significantly reduce the computational complexity while maintaining pragmatic error probability. Reported results reveal significant reduction in computational complexity and massive MIMO configurations is made feasible.