Maximum-Power and Amplitude-Equalizing Algorithms for Phase Control in Space Diversity Combining

Maximum-Power and Amplitude-Equalizing Algorithms for Phase Control in Space Diversity Combining By P. D. KARABINIS (Manuscript received October 12, 1981) Space diversity receivers equipped with continuous combiners have, in recent years, found wide use in terrestrial microwave radio systems as a means of mitigating the effects of multipath fading. An analysis of two phase-control algorithms for space diversity combining, comparing the performance capabilities of a maximum-power and an amplitude-equalizing algorithm, is presented in this paper. The extended capabilities of the equalizing algorithm in mitigating linear and quadratic channel distortions are investigated through computer simulations. A reduction in digital radio outage time afforded by the equalizing algorithm (relative to that of the maximum-power algorithm) is approximated for over-water-paths where it is assumed that fading can be described in terms of a two-ray fading model. For the model chosen, we show that the additional outage reduction owing to the equalizing phase-control algorithm is highly dependent on the statistics of the multipath delay parameter, T, and can vary from unity to a factor of five for different probability-density functions of T.