无线异构网络中用户选择算法研究

发布时间：2018-07-21 20:51

【摘要】：无线异构网络由于其组网方便,覆盖全面以及较高的频谱利用率等众多优势近年来受到越来越多的关注,成为5G的关键技术之一。无线异构网络主要是指在宏基站的覆盖范围内,部署微基站、微微基站、中继基站等小型基站加强针对性覆盖,通过缩短用户与基站间的距离增加用户接收信号的强度。同时,异构网络采用同频组网的方式有效缓解频谱资源稀缺带来的压力。然而,在宏基站的覆盖范围内部署小型基站导致网络拓扑结构变的更加复杂,宏蜂窝和微蜂窝之间的跨阶层小区间干扰成为了异构网络性能提高的瓶颈。因此对异构无线网络中的干扰进行抑制是目前的研究热点之一。本文针对无线异构网络中存在的跨阶层干扰,提出了几种在不同网络模型下的用户选择算法,充分利用多用户分集增益,降低跨层干扰对异构网络性能的影响,提升用户体验。首先,针对基站端配置多根收发天线、用户单天线接收的无线异构网络中的跨层干扰问题,提出了一种基于分组的用户选择算法。该算法保证了用户在任意分布情况下,基站都可以选出受跨层干扰最小的用户,获取用户的分集增益,降低系统的跨层干扰;其次,针对基站端与用户端同时配置多根收发天线情况下的无线异构网络中的跨层干扰问题,提出了综合考虑信道的方向信息与信道质量信息的用户选择算法,此部分算法分别以弦距离、弦距离与信道范数的平衡以及加权函数作为衡量指标,并对三种不同指标算法做了详细分析。最后,针对基站端有限反馈量化误差和跨层干扰残留误差问题,提出了一种基于有限反馈的跨层干扰消除用户选择算法,算法将量化误差对用户选择与干扰消除的影响降到最低,有效提升了异构网络的系统性能。仿真结果表明,本课题所提出的用户选择算法能够在相应系统模型下有效降低异构网络中跨阶层干扰,提升系统性能。
[Abstract]:Wireless heterogeneous networks have attracted more and more attention in recent years due to their advantages of convenient networking, comprehensive coverage and high spectral efficiency, and have become one of the key technologies of 5G. Wireless heterogeneous network mainly refers to the deployment of micro-base station, pico-base station, relay base station and other small base stations to strengthen targeted coverage, and increase the intensity of received signals by shortening the distance between users and base stations. At the same time, the heterogeneous networks use the same frequency network to effectively relieve the pressure caused by the scarcity of spectrum resources. However, the deployment of small base stations within the base station coverage makes the topology of the network more complex, and the cross-layer intercellular interference between macro cell and microcellular becomes the bottleneck of improving the performance of heterogeneous networks. Therefore, the suppression of interference in heterogeneous wireless networks is one of the research hotspots. In this paper, several user selection algorithms based on different network models are proposed to reduce the influence of cross-layer interference on heterogeneous network performance and improve user experience by making full use of multi-user diversity gain. Firstly, a packet based user selection algorithm is proposed to solve the cross-layer interference problem in heterogeneous wireless networks with multiple transceiver antennas and single user antennas at the base station. The algorithm ensures that the base station can select the user with the least cross-layer interference under arbitrary distribution, obtain the diversity gain of the user, and reduce the cross-layer interference of the system. Secondly, In order to solve the problem of cross-layer interference in heterogeneous wireless networks with multiple transceiver antennas at the base station and the client side at the same time, a user selection algorithm considering both the channel direction information and the channel quality information is proposed. In this part, the chord distance, the balance between chord distance and channel norm and the weighting function are taken as the measurement indexes, respectively, and three different index algorithms are analyzed in detail. Finally, aiming at the problem of quantization error of finite feedback and residual error of cross-layer interference at base station, a cross-layer interference cancellation user selection algorithm based on finite feedback is proposed. The algorithm minimizes the impact of quantization errors on user selection and interference cancellation, and effectively improves the performance of heterogeneous networks. Simulation results show that the proposed user selection algorithm can effectively reduce cross-class interference in heterogeneous networks and improve system performance under the corresponding system model.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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