CIF: Small: A Cross-Tier Approach to Interference Management in Wireless Heterogeneous Networks

在异构无线网络中，由于第二层低功率微/皮科/毫微微基站和高功率宏基站之间的频率共享，干扰已经成为主要的性能限制因素。本计画探讨异质性无线网路干扰管理的理论与实务问题，首先将找出计算上难以处理的干扰管理问题，然后以多项式的复杂度来近似求解。特别强调的是所提出的算法的分布式实现。一个统一的共同层和跨层的方法将开发联合用户准入，用户基站的关联，功率控制，用户分组以及收发器的设计。这项研究的核心是联合优化用户基站的关联，发送/接收波束成形器，用户调度以及部分联合传输之间的一个子集的基站。该方法将干扰管理问题转化为一个等价的高维优化问题，并探索有效的迭代更新，可以分解到基站，用户和频隙。在整个研究中，先进的优化技术将是各种干扰管理算法的发展的关键。本研究所提出的方法将为异构网络中的干扰抑制提供有效的手段，并显著提高网络吞吐量和用户服务质量。

In a heterogeneous wireless network, interference has become the dominant performance limiting factor due to frequency sharing between the second tier low powered micro/pico/femto base stations and the high powered macro base stations. This project deals with several theoretical and practical aspects of interference management for the heterogeneous wireless networks.The proposed research will first identify the classes of interference management problems that are computationally intractable, and then show how well they can be approximately solved with a complexity that is polynomial in the problem size and the solution accuracy. Special emphasis is given to the distributed implementation of the proposed algorithms. A unified co-tier and cross-tier approach will be developed for joint user admission, user-base station association, power control, user grouping as well as transceiver design. Central to this study is to jointly optimize user-base station association, transmit/receive beamformers, user scheduling as well as partial joint transmission among a subset of base stations. The proposed approach will transform the interference management problem into an equivalent higher dimensional optimization problem and explore efficient update of iterates that can be decomposed across base stations, users and frequency slots.Throughout this research, advanced optimization techniques will be the key to the development of various interference management algorithms. The methodologies developed in this research will provide effective means to mitigate interference in heterogeneous networks and significantly improve the network throughput as well as the users quality of service.