A heuristic decomposition methodology for channel assignment problems in mobile communication systems

The present paper puts forward an efficient ‘First decompose, then Solve’ solution strategy for Channel Assignment Problems (CAP) in Cellular Communications System. The underlying objective of the decomposition technique presented in this paper is that the Interference Graph (IG) developed for intractable CAP be broken down into sub-graphs (Channel Assignment Sub-Problems, CASP’s) of lower complexity and dimensionality by identifying the mutual interference patterns among Base Stations (BS’s). The IG decomposition problem itself is a NP-Complete Problem. In [1], the author had proposed a Tree-search algorithm for decomposing the IG. In the present paper, an alternative heuristic decomposition methodology is presented. The motivation for development of the heuristic technique is to bi-partition the IG using minimal computational resources. However, not guarantee of the global optimality of the partitioning solution obtained using the proposed decomposition technique is provided. The small-scale CASP associated with each subgraph developed is then solved using a conventional method [2]. The collection of solutions to the subproblems is then solution to the large-scale original CAP. The application of the proposed decomposition technique to a number of CAP demonstrates the computational advantage associated with using the proposed methodology.