Interference Mitigation Via Cross-Tier Cooperation in Heterogeneous Cloud Radio Access Networks
Interference Mitigation Via Cross-Tier Cooperation in Heterogeneous Cloud Radio Access Networks
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DOI：
10.1109/tccn.2019.2957457
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发表时间：
2020-03
影响因子：
8.6
通讯作者：
Yujie Tang;Peng Yang;Wen Wu;J. Mark;X. Shen
中科院分区：
文献类型：
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作者：
Yujie Tang;Peng Yang;Wen Wu;J. Mark;X. Shen
在本文中，提出了 H-CRAN 中的跨层协作框架来减轻层间干扰。具体来说，小小区远程无线电头端（S-RRH）充当多个宏小区用户（MUE）的中继，并从多个MUE获得时隙的一部分作为奖励。通过协作，S-RRH可以获得额外的频谱资源来为作为次要用户的小小区用户(SUE)提供服务，而作为主要用户的MUE可以提高其数据传输效用。合作问题被表述为混合整数规划，这是 NP 困难的。为了解决这个问题，我们将合作问题转化为联合合作时间和功率分配问题以及合作者选择问题。首先，我们解决联合合作时间和功率分配问题，以获得所有可能合作对的最大合作效用。我们通过使用线性独立约束条件和 Karush-Kuhn-Tucker 条件导出分配问题的封闭式解。然后，我们通过双边匹配算法解决合作者选择问题。大量的仿真结果表明，采用所提出的协作框架可以提高宏蜂窝网络和小蜂窝网络的效用，并且协作者选择结果稳定且接近最优。
In this paper, a cross-tier cooperation framework in H-CRAN is proposed to mitigate inter-tier interference. Specifically, a small cell remote radio head (S-RRH) acts as the relay for multiple macrocell users (MUEs), and obtains a fraction of time slot from multiple MUEs as a reward. Through the cooperation, the S-RRHs can obtain extra spectrum resource for serving small cell users (SUEs) which are secondary users, while the MUEs which are primary users can improve their data transmission utility. The cooperation problem is formulated as a mixed integer programming, which is NP-hard. To solve this problem, we transform the cooperation problem into a joint cooperation time and power allocation problem and a cooperator selection problem. First, we solve the joint cooperation time and power allocation problem to obtain the maximum cooperation utility of all the possible cooperating pairs. We derive the closed-form solution for the allocation problem by using linear independence constraint qualification and Karush-Kuhn-Tucker conditions. Then, we solve the cooperator selection problem by a two-sided matching algorithm. Extensive simulation results show that the utility of macrocell networks and small cell networks can be improved by adopting the proposed cooperation framework, and the cooperator selection result is stable and close-to-optimal.