In this study, the authors propose a user association scheme with quality of service support for load balancing in heterogeneous cellular networks (HCNs), which jointly considers user's achievable rate and load le...
详细信息
In this study, the authors propose a user association scheme with quality of service support for load balancing in heterogeneous cellular networks (HCNs), which jointly considers user's achievable rate and load level of each BS instead of only utilising the former. To reveal how HCNs should self-organise, the authors formulate it as a network-wide weighted utility maximisation problem. Note that the formulated problem is a non-linear mixed-integer one, and its optimal solutions may be very difficult to be found when it is large-scale. To solve the proposed problem, the authors design a low-complexity distributed algorithm via dual decomposition. Numerical results show that, compared with the range expansion association (REA) and best power association (BPA), the strategy has a higher load balancing level (LBL) and a lower call blocking probability (CBP). Meanwhile, the proposed algorithm occupies a very fast convergence rate when its parameters are set properly.
In this paper, we propose a joint relay selection and power allocation algorithm for a multi-user, multi relay cellular network using decode-and-forward cooperation strategy with imperfect knowledge of channels. The o...
详细信息
ISBN:
(纸本)9781424492688
In this paper, we propose a joint relay selection and power allocation algorithm for a multi-user, multi relay cellular network using decode-and-forward cooperation strategy with imperfect knowledge of channels. The objective is to minimize the total uplink power of the network taking each user's target data rate as the quality of service constraint under imperfect channel state information (CSI), assuming some statistical knowledge is known about the channel estimation error. Joint relay selection and power allocation is a mixed integer programming problem which is combinatorially hard. For that an efficient sub-optimal solution with lowcomplexity using convex relaxation approach is proposed. After relay selection, a centralized power allocation scheme is developed to optimally allocate the power among the users and the selected relay nodes. Then a low-complexity distributed algorithm is proposed based on a standard primal decomposition approach, where each selected relay can independently minimize its own power. Numerical results demonstrate the effectiveness of the proposed algorithms.
暂无评论