Resource allocation based on subcarrier exchange in multiuser OFDM system  

作　　者：WANG Ye ZHANG QinYu ZHANG NaiTong 

机构地区：[1]Harbin Institute of Technology Shenzhen Graduate School,Communication Engineering Research Center [2]Harbin Institute of Technology,Communication Research Center

出　　处：《Science China(Information Sciences)》2013年第1期180-193,共14页中国科学（信息科学）（英文版）

基　　金：supported by National Basic Research Program of China (Grant No. 2009CB320402);National Natural Science Foundation of China (Grant No. 61032003)

摘　　要：Multi-user orthogonal frequency division multiplexing （OFDM） is one of the most important tech- niques for next-generation wireless communication systems. The sum capacity and proportional fairness index are two important metrics in OFDM adaptive resource allocation. In existing researches, the two metrics have individually yielded approximately optimal solutions. However, as the two goals seem to contradict each other, it means that they cannot achieve optima simultaneously. This paper presents a resource allocation algorithm based on subcarrier exchange. By relaxing the fairness index, the proposed algorithm can dynamically adjust the fairness requirements. Furthermore, By considering a criterion that minimizes the loss of sum capacity, the proposed algorithm can balance the tradeoff between fairness and sum capacity. In contrast to existing algorithms, our proposal improves performance by approximately 30~ in terms of sum capacity, at the expense of approximately 10% reduction in proportional fairness. Moreover, if a malicious user exists, each user in the system can obtain higher ergodic capacity compared with the conventional algorithms. To decrease the complexity, a low-complexity simplified alternative is presented, which outperforms the conventional algorithm with an increase in the number of users. Four numerical simulations are carried out to verify the efficiency and effectiveness. Finally, we discuss in detail the computational complexity of the proposed algorithm.Multi-user orthogonal frequency division multiplexing （OFDM） is one of the most important tech- niques for next-generation wireless communication systems. The sum capacity and proportional fairness index are two important metrics in OFDM adaptive resource allocation. In existing researches, the two metrics have individually yielded approximately optimal solutions. However, as the two goals seem to contradict each other, it means that they cannot achieve optima simultaneously. This paper presents a resource allocation algorithm based on subcarrier exchange. By relaxing the fairness index, the proposed algorithm can dynamically adjust the fairness requirements. Furthermore, By considering a criterion that minimizes the loss of sum capacity, the proposed algorithm can balance the tradeoff between fairness and sum capacity. In contrast to existing algorithms, our proposal improves performance by approximately 30~ in terms of sum capacity, at the expense of approximately 10% reduction in proportional fairness. Moreover, if a malicious user exists, each user in the system can obtain higher ergodic capacity compared with the conventional algorithms. To decrease the complexity, a low-complexity simplified alternative is presented, which outperforms the conventional algorithm with an increase in the number of users. Four numerical simulations are carried out to verify the efficiency and effectiveness. Finally, we discuss in detail the computational complexity of the proposed algorithm.

关 键 词：multiuser OFDM resource allocation capacity proportional fairness computational complexity 

分 类 号：TN919.3[电子电信—通信与信息系统]