Summary
Asia-Pacific Conference on Communications
2015
Session Number:14-PM1-B
Session:
Number:14-PM1-B-1
Dynamic Almost Blank Subframe Assignment Method with Power Control Subframe for User Fairness
Masayoshi Ozawa, Tomoaki Ohtsuki,
pp.57-61
Publication Date:2015/10/14
Online ISSN:2188-5079
DOI:10.34385/proc.28.14-PM1-B-1
Summary:
In long term evolution (LTE), heterogeneous network (HetNet) is constructed to increase network capacity. In HetNet, low transmit power base stations (BSs) such as femto-BSs are deployed in an indoor within the coverage of macro cells. Since BSs are close to each other in HetNet, indoor or cell-edge users are likely to experience outage due to inter-cell interference. Therefore, almost blank subframe (ABS) techniques emerge as inter-cell interference mitigation technique in time region. One of the conventional ABS techniques is dynamic ABS assignment, which is able to adapt to interference circumstances to protect the cell-edge users more. In the dynamic ABS assignment method, a BS dynamically allocates ABS to its subframe based on surrounding circumstances. However, the resource utilization of BSs decreases, because the number of ABS assignments increases in the dense BS deployment. This results in low sum rate. In addition, if the number of ABS assignments increases, user fairness becomes impaired due to the difference of the number of users which each BS serves. In this paper, we propose a dynamic ABS assignment method with power control subframe to improve sum rate and user fairness together. Each BS receives feedback from surrounding BSs and users, and chooses its subframe assignment based on the received feedback. Simulation results show that the proposed method improves the sum rate and user fairness compared with the conventional dynamic ABS assignment method, while achieving a similar user outage ratio.