RF link power control with field test data

Associated with the rapid concentration of forces there is the issue of EMC/EMI problems among various radios in a theater. The general issue is about how various narrow band radios can be brought to use in a battle field with automated RF power management. The study in this paper is restricted to point to point link power control. The concept of power management should also be applied to a number of radios in a network structure. In order to achieve minimum possible cochannel interference a party at the link ends should radiate minimum power. It should be only enough to establish an adequate service (BER) for that particular distance and no more. In an ideal situation the path loss is proportional to the logarithm of the distance and transmission frequency. In a real situation the path loss is also affected by the terrain features. Radio links in battle field are fading limited and interference limited from all sources. Channel fading has been attributed to multipath, scattering, and shading. In this study an UHF link with 19.2 kilo baud modems were setup between a base node and a mobile node. The goal is to study possible power control algorithms that can track a minimal RF power for a particular BER. Output RF power is attenuated at increments in the algorithm. A range of RF power is allowed to change until a preset BER is achieved. The field tested data and the simulation results are presented.