The Optimization And Application Of The Frequency Assignment For Mobile Communication Based On Graph Coloring Theory

For the wireless communication system, radio frequency resource is very precious andlimited. At present, the increasingly development of communication technology and theexplansions of the communication network is further intensifying the contradiction betweenthe limited frequency resource and the increasing demand of the frequency. In order to solvethis problem, peoples try to a lot of methods, including the reasonable configuration offrequency resources and the frequency multiplexing technology.The reasonable configuration of frequency resources also calledFrequency-Assignment-Problem; it is a kind of means and measures in order to maximizethe use of available frequency resources. It must take account of the interferencecharacteristics between frequencies and try to meet the needs of users during configuration.For mobile operators, the reasonable configuration of frequency resources has greateconomic benefit.However, the frequency assignment problem is a typical NP complete problem in thepermutation and combination. Some researchers use the classical solution in the permutationand combination such as the heuristic algorithms, genetic algorithm and graph theoryalgorithm to solve them.In this paper, I try to use the theory of graph coloring to solve the frequency assignmentproblem, and on the basis of reference to previous graph theory algorithm, proposed the newcalculation method of Double-layer-model in the first time.Through decompose algorithm step with a simple way, we can effectively reduce theamount of computation, improve the processing speed, and do not affect the communicationindicators.The paper is through a brief introduction to the in-depth study of thedouble-layer-model to explain its context： firstly, it briefly discusses about the backgroundand significance of the research； secondly, it introduces the mobile communication frequency allocation on the basis of content as well as several frequencies allocationalgorithms； finally, it establishes double-layer-model based on graph theory. Through theresearching and calculating, we can get the feasibility of the algorithm and simplicityconclusions. At the same time, the use of this method in practical operation has also beenconfirmed.