Cooperative Selection Combining in Body Area Networks: Switching Rates in Gamma Fading

An analytical expression for the switching rate of three-branch selection combining is derived for independent and identically distributed (i.i.d.) gamma fading. This expression can also be applied to lognormal, normal, Nakagami-m, Rayleigh, Weibull and generalized-gamma (or α - μ) fading channels. I.i.d. gamma fading models the `everyday' cooperative body area networks (BAN) well. Results from BAN measurements approximate three-branch analytical results, and branch approximate independence is validated. Results are also presented for two-branch cooperative selection combining. It is shown that `everyday' switching rates are slow enough to allow cooperative BAN.