Simple accurate closed-form approximations for the crossing rates of Weibull fading channels in multibranch diversity systems

In this paper, we propose accurate closed-form approximate expressions for the level crossing rate (LCR) of the envelope of equal-gain and maximal-ratio combining receivers operating on independent Weibull fading channels. Due to the inherent intricacy of the exact formulation, in which the LCR is given in terms of multiple integrals, our closed-form approximations play a crucial role in this issue as far as the computational evaluation is concerned. In addition, sample numerical curves are plotted to illustrate the excellent agreement between exact and closed-form approximate formulations for such diversity scenarios.