Maximal-Ratio Based Switch-and-Stay Combining for Dual-Branch Systems

A hybrid combining technique is one of the hot topics in the diversity research field because of the excellent overall performance compared with pure combining techniques. A hybrid maximal-ratio-based switch-and-stay combining (M-SSTC) scheme, for dual-branch systems, is proposed in this paper to enhance the existing SSTC-type combining techniques. According to this paper, the problem of the available solutions is that they are valid only when both the branches are poor, leading the performance gain very limited. Thus, we make an attempt to adopt the maximal-ratio combining technique to overcome this disadvantage. By designing reasonable switching logic, M-SSTC can improve the performance of the diversity system as much as possible while keeping its complexity in a low level. Based on the Markovian property of the M-SSTC's output state sequences, the outage probability performance of M-SSTC is analyzed, and the closed-form expression is also presented. Finally, simulation results validate the theoretical results and show the advantages of M-SSTC over the available schemes.