蜂窝终端直通混合网络中动态频谱高效利用技术研究

发布时间：2018-03-24 17:23

本文选题：混合网络　切入点：频谱感知　出处：《北京邮电大学》2014年博士论文

【摘要】：随着无线通信技术的发展,无线网络环境日益复杂,混合网络的概念由此提出,用于定义传统蜂窝网络与终端直通网络共存的无线混合式网络场景。该场景下的研究意义有二：理论方面,在频谱资源日益紧张的情况下,场景中重用频谱的通信方式可以有效提高频谱利用率；实际应用方面,该场景符合运营商的利益,终端到基站的链路减少,不但使得链路间干扰减少,而且也减少重复发送相同数据的链路,从而提高频谱的实际利用率。本文正是研究蜂窝终端直通混合网络中动态无线频谱资源的高效利用问题。针对混合网络场景中的频谱检测技术、基站辅助的半集中式频谱共享技术、以及联合终端直通用户的功率控制与频谱接入的分布式资源调度相关技术三个方面,以提高以提升混合网络整体性能为目标,研究高效利用频谱资源的方法。首先,本文针对宽频带信号的能量检测技术,设计了最优的门限判决准则；随后,针对混合网络中上行频谱资源共享的场景,设计了可以同时体现两种终端用户比例公平性在基站辅助模式下的调度策略；最后,针对混合网络直通终端频谱接入的场景,为终端直通用户设计了分布式联合信道功率控制与频谱选择接入的调度策略。论文主要创新性工作如下：第一,为了实现终端直通用户重用蜂窝频谱资源进行通信,研究了蜂窝终端直通混合网络中的频谱感知技术：首先,针对宽频带信号,结合虚警概率门限和检测概率门限,并利用最小代价函数推导出最小代价门限的闭式解,并在检测性能约束的条件下分析出性能指标对能量检测最优判决门限的限制；其次结合时域上的观测时长对最小代价门限的约束,设计了最优的判决门限准则；最后通过之后的数值仿真以及对观测时长进行分段的检测性能分析验证了提出的判决门限准则的最优性。第二,研究了基于获取上述频谱感知信息的基础上,混合网络中蜂窝用户与终端直通用户的上行频谱资源的共享机制,设计了一种基站辅助下同时为两类终端用户分配频谱资源与功率的策略：首先,通过把资源分配问题建模为两类终端的和速率最大化的优化问题,其约束条件中设置了终端直通用户的用户速率要求保障机制,用以实现两类用户的比例公平调度；其次,通过拉格朗日因子算法以及KKT条件对上述问题进行求解,根据闭式解得出结论：对于两类终端来说,频谱资源的选择与功率分配之间是互为条件选择；最后,按照上述结论给出该策略的具体算法,并进一步验证了该策略在公平性和吞吐量优异性。第三,研究在混合网络中终端直通用户获得频谱感知信息之后,自主选择接入蜂窝上行频谱及完成功率控制对混合网络性能的影响：首先,基于终端直通用户的系统总吞吐量进行最优化数学建模,并通过以总吞吐量和接入链路数最大化两种首要因素分别对最优化问题进行求解；其次,按照结果设计两种分布式终端频谱接入选择策略,并针对链路尝试接入的两种顺序与上述策略搭配执行,给出了相应的分布式资源调度的具体方案：最后,为了证明所提方案的有效性,论文进一步给出了新的调度方案策略与集中式调度策略的性能比较结果。
[Abstract]:With the development of wireless communication technology, wireless network environment is increasingly complex, the concept of hybrid network is presented, the definition of the traditional cellular network and terminal through wireless hybrid network scenarios for network coexistence. The significance of this research has two scenarios: theory, spectrum resources in the increasingly tense situation, communication scene spectrum reuse can effectively improve the spectrum utilization rate; practical application, the scene in the interest of operators, terminal to base station link reduced, not only makes the inter link interference reduction, but also reduce the repetition of the same data link to send, so as to improve the utilization of the spectrum.
This paper is a study of the cellular terminal through the efficient use of dynamic spectrum resource in hybrid network. According to the spectrum detection technology of hybrid network scene, semi centralized spectrum sharing technology base station assisted, and the joint terminal through distributed power control and spectrum resource user access scheduling technology in three aspects, in order to improve to enhance the overall performance of the hybrid network as the goal, method of spectrum resources and efficient use of research. First of all, based on the energy detection technology of wideband signal, design the optimal threshold criterion; then, for the sharing of uplink resources in a hybrid network scenario, design can also reflect the scheduling strategy of two terminal users proportional fairness in base station the auxiliary mode; finally, aiming at the hybrid network terminal through spectrum access scenario for distribution through the user terminal design Scheduling strategy for joint channel power control and spectrum selection access. The main innovative work of this paper is as follows:
First, in order to realize the reuse of spectrum resources through the user terminal cellular communication on the cellular terminal through spectrum sensing technology in hybrid network: first of all, according to the broadband signal, combined with the false alarm probability and detection probability threshold threshold, closed solution and use the minimum cost function to derive the minimum cost threshold, and the analysis of the performance limit the index of optimal decision threshold of energy detection in the detection performance constraints; secondly the length of observation time minimum cost threshold constraint, the optimal design of threshold criteria; finally, through numerical simulation and verification after the optimality of the proposed threshold criterion for performance analysis of detection segment length the observation.
Second, based on the basis of obtaining the spectrum sensing information sharing mechanism, through the uplink resources users of cellular users and terminal hybrid networks, designed a base station assisted at the same time as the two terminal user resources and power spectrum allocation strategy: first, through the resource allocation problem is modeled as optimization problems the terminal two and the maximum rate, the constraints set in the terminal through the user's user rate requirements guarantee mechanism, to realize the two kinds of users proportional fair scheduling; secondly, through the Lagrange factor algorithm and KKT condition to solve the above problems, based on the closed solution of the conclusion: for two types of terminal between, selection and power allocation of the spectrum resources are selected according to the specific conditions; finally, the conclusion is given the algorithm strategy, and further validates the strategy It is slightly better in fairness and throughput.
Third, the research in hybrid network terminal through the user access spectrum sensing information, choose the access to the cellular uplink power control and influence on the performance of the hybrid network: first, optimize the mathematical modeling through the user's terminal system based on total throughput, and through to the total throughput and access link to maximize the number of two primary factors respectively. The optimization problem is solved; secondly, according to the design of two kinds of distributed spectrum access terminal selection strategy, and for the two order and the link to access the collocation strategy implementation, a scheme of distributed resource scheduling accordingly. Finally, in order to prove the validity of the proposed scheme, the paper further gives the performance of the scheduling scheme strategy and centralized scheduling strategy of the new results.

【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5

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