Compatibility and the Frequency Selection Problem

An automated model that calculates the frequency separation requirements for interference free operation of electronic systems located in a given environment is described. Using these frequency separation requirements, the model assigns a channel to each system in the environment based on the frequencies available to each. The model calculates inter system, antenna coupled interference levels only. It uses an iterative, but nonexhaustive, process which attempts to develop a compatible assignment. Preassignment checks are performed to determine if a complete assignment is impossible based on the number of frequencies available to each system and the separations between these frequencies. If an assignment is impossible, a partial assignmnent with the least number of deletions restults. Using the preassignment checks, the model can be used to determine a channel scheme for a new system that will conserve spectrum space and allow compatible operation in any given environment. The results of a recent application of the model to an environment of microwave landing guidance systems including the proposed MLS is given.