The Research Of Frequency Assignment Technology In The Wireless Electromagnetic Spectrum Management

With the rapid development of wireless communication technologies, the demand of various radio services with spectrum resource have been rising promptly, the electromagnetic environment is getting more and more complex, the contradictory of supply and demand for electromag netic spectrum becomes incisive day by day, thus it is extraordinarily important to study the technologies of frequency assignment. The key technologies-modeling and algorithm-of the large-scale and dynamic frequency assignment problems are studied thoroughly in the network.Firstly, a mathematical model has been built, composed of two parts, certain factors affecting the electromagnetic environment have been transformed to the constraints, and then the cost function has been constructed containing the penalty factors and the restraint relations, so the model enables the electromagnetic environment to be described quantitatively. The frequency assignment algorithms based on the intelligent optimization algorithm designed in the paper have used the model, considering the co-channel interference, adjacent channel interference and co-site interference, three kinds interference being close to the actual situation.Secondly, a frequency assignment algorithm based on tabu search is presented. The simulation results indicate that this algorithm could solve the large-scale network links frequency assignment problem in such a short time, and obtain good solution.It has solved the difficult problem that frequency assignment problems run time increases "explosive" exponentially with the network scale.Finally, try to take advantage of the discrete particle swarm optimization algorithm to handle radio communication network dynamic frequency assignment problem in battlefield conditions. Under the conditions of complex battlefield radio communications network frequency equipment to complete real-time, dynamic frequency selection situation modeling, a mathematical model based on discrete particle swarm optimization algorithm for dynamic frequency assignment problem. Simulation know, when carried out to a large-scale radio communication network frequency assignments, the algorithm can be implemented in a very short time, fast, stable convergence, but dropped to the lowest level within a very short time with the frequency conflict Level these are in line with the completion of the optimal dynamic frequency assignment requirements.