Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article A Utility-Based Downlink Radio Resource Allocation for Multiservice Cellular DS-CDMA Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 76193 11 pages doi 2007 76193 Research Article A Utility-Based Downlink Radio Resource Allocation for Multiservice Cellular DS-CDMA Networks Mahdi Shabany 1 Keivan Navaie 2 3 and Elvino S. Sousa1 1 Edward S. Rogers Sr. Department of Electrical and Computer Engineering University of Toronto Toronto Ontario Canada M5S 3G4 2 Department of Electrical and Computer Engineering Faculty of Engineering Tarbiat Modares University . Box 14155-4838 Tehran Iran 3 The Broadband Communications and Wireless Systems BCWS Center Department of Systems and Computer Engineering Carleton University Ottawa Ontario Canada K1S 5B6 Received 30 May 2006 Revised 1 December 2006 Accepted 8 January 2007 Recommended by Wei Li A novel framework is proposed to model downlink resource allocation problem in multiservice direct-sequence code division multiple-access DS-CDMA cellular networks. This framework is based on a defined utility function which leads to utilizing the network resources in a more efficient way. This utility function quantifies the degree of utilization of resources. As a matter of fact using the defined utility function users channel fluctuations and their delay constraints along with the load conditions of all BSs are all taken into consideration. Unlike previous works we solve the problem with the general objective of maximizing the total network utility instead of maximizing the achieved utility of each base station BS . It is shown that this problem is equivalent to finding the optimum BS assignment throughout the network which is mapped to a multidimensional multiple-choice knapsack problem MMKP . Since MMKP is NP-hard a polynomial-time suboptimal algorithm is then proposed to develop an efficient base-station assignment. Simulation results indicate a significant performance improvement in terms of achieved utility and packet drop ratio. Copyright 2007
