Third Order Intermodulation Interference--Bounds and Interference-Free Channel Assignment

In this paper a relationship between difference triangles and third order intermodulation interference is demonstrated, and two applications of this relationship are developed. In the first application, the relationship allows us to find intermodulation-free channel assignments where such arrangements are possible. The second application concerns cases where this is not possible. In the second application, arguments connected with difference triangles are used to bound, from below, the total intermodulation interference and the maximum interference falling on any assigned channel for the optimum channel assignment. To determine the tightness of this bound, a random coding type argument is used to bound the total intermoduiation for the optimum channel assignment from above, and an upper bound on the maximum intermod is established using previously performed computer experiments.