A New Approach for Sub-Channels Assignment in Downlink Fourth Generation Mobile Systems

Abstract

Problem statement:We proposed a new heuristic method for subchannels allocation problem in the context. Approach: In this system, OFDM transmission method has been used, in order to reduce the effect of multipath fading, OFDMA to achieve multiple access schemes and flexibility in resource allocation. Results: An adaptive method for subchannels allocation is necessary in order to exploit the multiuser diversity, to respect real time constraints and to maximize the capacity system. The proposed algorithm is based in the Channel State Information (CSI) of total mobiles stations present in the cell. The idea of this method is based in the statistic parameters of the gain of frequency response channel for every mobile station. These parameters are the key to organize the different MS's and subchannels priority. Conclusion/Recommendations: Numerical results showed that the proposed algorithm outperforms an allocation scheme in terms of Bloc Error Rate, Higher system capacity and Fairness among active users, compared to others previous methods.