The primary environmental factors that influence the consistent robustness of a radio link are multipath/fading and antenna polarization/diversity. These phenomena can be either constructive or deconstructive to the quality of the radio link depending on many given circumstances. While antenna diversity (multiple antennas in different locations and with different orientation) is useful at recovering signal integrity and retaining link budget from the effects of the environment, many designers opt not to use it, as the trade offs of extra hardware and software load can be quite high in their applications.

This article looks at the underlying problem, the principles of antenna diversity, and how RSSI (received signal strength indicator) can be used in a software-based algorithm to reduce the processor load when managing multiple antennas.