Necessary Condition-Based Detector for Generalized Space Shift Keying MIMO Systems

In this letter, we present a low-complexity detection algorithm for generalized space shift keying MIMO systems. First, the maximum likelihood detection is posed as a binary quadratic programming (BQP) problem. Then, we derive an optimal decision rule based on the necessary global optimality condition of BQP. Using this rule, most entries of solution can be determined optimally with only O(3N(t)) per-bit complexity. Furthermore, taking advantage of the determined entries, the original programming can be reduced to a smaller-scale one only including the undetermined entries. Finally, we can use some conventional detectors to solve the remained small-scale problem with a lower complexity. Simulation results substantiate the performance of the proposed detector.