The power-ordered intermodulation algorithm

The authors describe the power-ordered intermodulation (IM) algorithm, an efficient technique for determining interference levels due to IM in the power bank of a system with wideband RF architecture. The key feature of the algorithm is that the set of IM products is partitioned into subsets, each having the property that all IM products in the subset can be enumerated in order of decreasing power level. If a product in a particular subset is negligibly weak, then the subsequent products in that subset can be automatically eliminated. The power-ordered IM algorithm is significantly faster than other IM algorithms considered. This algorithm greatly reduces the execution time for a typical analysis of shipboard radio communications. For a case with eight transmitters operating simultaneously, the execution time is typically reduced by a factor of 200 or more, depending on the power levels of the fundamental signals