Three multibranch switch-and-stay combining (MSSC) schemes are analyzed for Rayleigh fading channels, where different\r\ndecision statistics for antenna switching (i.e., switch statistic) are used. Let a and r denote the fading factor and the received\r\nbaseband signal of a diversity branch, respectively. In contrast to the traditional MSSC that uses the faded signal-to-noise ratio\r\n(SNR) of diversity branches as the corresponding switch statistic, to enhance the receiver performance, |r|, |ar|, and a new linear\r\ncombination of a and |r| are used as switch statistics of the three MSSC schemes, respectively. For performance evaluation, the\r\nbit error rate (BER) of BPSK is derived for the three MSSC schemes over both independent-and-identical distributed (i.i.d.) and\r\nindependent-and-nonidentical distributed (i.n.d.) Rayleigh fading channels. To pursue optimal performance, the locally optimal\r\nswitch threshold (ST) of each MSSC scheme is obtained for general i.n.d. fading channels. In addition, the locally optimal ST\r\nbecomes the globally optimal ST for i.i.d. channels. Numerical results based on the analysis and simulations are presented. In\r\ncontrast to the MSSC over i.i.d. fading channels, we will show that the performance of MSSC schemes can be improved by\r\nincreasing the number of branches, if i.n.d. channels are considered.
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