  We study the performance of a selection combining (SC) receiver operating
over independent but non-identically distributed log-logistic ($\mathcal{LL})$
fading channels. We first characterize the statistics of the output
instantaneous signal-to-noise ratio (SNR) of the SC receiver. Based on the SNR
statistics, we derive exact analytical expressions, in terms of multivariate
Fox H-functions, for the outage probability, the average bit error rate, and
the ergodic capacity. We also derive exact expressions for such performance
measures when all channels are independent and identically distributed, as a
special case. Furthermore, we deduce simplified asymptotic expressions for
these performance metrics assuming high values of average transmit SNR. To
demonstrate the applicability of our theoretical analysis, we study the
performance of an SC receiver in underwater optical wireless communication
systems. Finally, we confirm the correctness of the derived analytical results
using Monte Carlo Simulations.
