Generalized selection combining with double threshold and performance analysis

In this paper, we propose a new diversity combining scheme to save power, which is called as the generalized selection combining with double threshold (DT-GSC). It selects the branch whose SNR is above an input threshold to combine, and this process will keep running until the combined output SNR is larger than an output threshold or until all paths are examined. The values of both thresholds are required to be predetermined on the basis of the practical communication conditions. For comparing the complexity of various combining schemes, we will show the mathematical formulas of the average number of path estimation and the average number of combined branches. Moreover, we will also compare the average bit-error-ratio performance of the proposed DT-GSC with absolute threshold GSC (AT-GSC) and output threshold MRC (OT-MRC). Numerical examples and simulation results show that the proposed DT-GSC leads to a lower complexity than the conventional AT-GSC and OT-MRC while it has a satisfactory performance.Copyright (c) 2012 John Wiley & Sons, Ltd.