Switching rate of dual selection diversity in non-isotropic IID fading channels

Switching rate plays an important role for system engineers in the design of selection diversity receivers. Switching antennas is similar to applying a step function to the receiver circuits, which causes transients in the receiver filters. These deleterious transients will corrupt channel estimation as well as creating “dead” time in the receiver filters. Recent work has studied the switching rates of selection diversity and hybrid selection diversity; however, these studies have examined exclusively isotropic scattering environments. No paper has been published on the switching rate of two-branch selection combining in a non-isotopic scattering scenario. The switching rate of a two-branch selection diversity combiner operating over multipath fading channels is studied. An analytical solution is derived for independent and identically distributed (i.i.d.) fading channels. Rayleigh and Rician cases with non-isotropic scattering are considered. Sample numerical results and discussion are presented. The results indicate that the switching rate is reduced in non-isotropic fading environments. Depending upon the characteristics of the non-isotropic environment, the switching rate may be reduced by as much as two to nine times relative to an isotropic environment.