高能效无线协作组播算法的研究

发布时间：2018-05-20 01:40

本文选题：协作组播 + 能量效率　；参考：《电子科技大学》2015年硕士论文

【摘要】：频谱、能耗和成本是移动通信网络可持续发展的三个关键因素。为了实现可持续发展,5th Generation(5G)系统相比4th Generation(4G)系统在频谱效率、能源效率和成本效率方面需要得到显著提升。组播通信能够利用单一频段服务多个用户,故其具有较高的频谱效率和能量效率。高能效的组播技术是未来5G系统中的研究重点。为了提高组播系统的能量效率,协作中继技术被引入组播通信系统,称为协作组播通信。协作组播传输由两个阶段组成。在第一阶段,基站广播相同的数据给所有用户,这导致小区中心的用户中断概率低而小区边缘用户中断概率高。也就是说,绝大部分小区中心用户成功接收到了数据;而大部分小区边缘用户不能成功接收数据。在第二阶段,一些成功用户作为中继将接收到的数据中继给失败用户。通过设计高效的协作组播中继算法,组播系统的能量效率能够得到有效的提高,从而满足5G系统在频谱利用率和能量效率上的跨越。因此,本文主要研究协作组播中的中继选择和功率控制算法。首先,本文提出了一种基于概率的双时隙协作组播中继算法。此算法先将组播系统的能量效率和中断概率约束建模成一个优化问题,接着分析了第二时隙成功用户的中继概率和中继功率对优化表达式的影响,得出了最优情况下的中继概率和中继功率。仿真结果表明,相比于传统的方法,我们的算法能达到较高的能量效率。然后,本文研究了双时隙协作组播中用户的中断概率分布与中继能量消耗的关系。我们发现小区中心用户和小区边缘用户不平衡的中断概率分布是导致中继功率浪费的主要原因。考虑到不同小区位置的用户在中断概率和能量效率方面的特点,本文给出了一种高能效的双时隙协作组播中继算法。特别地,本文给出了基于平衡的中断降低效率的最优算法,同时也找到了基于平衡的中断概率分布的次优算法。最优算法和次优算法的计算复杂度随基站与用户之间距离的采样数的增加而线性增加。仿真结果表明,相比于传统算法,我们的算法分别能够减少大约54%和40%的用户中继功率消耗。最后,我们总结了全文的贡献,并分析了未来研究的方向。
[Abstract]:Spectrum, energy consumption and cost are the three key factors for the sustainable development of mobile communication networks. In order to achieve sustainable development, the 5th Generation 5G system needs to be significantly improved in terms of spectrum efficiency, energy efficiency and cost efficiency compared with the 4th Generation 4G system. Multicast communication can serve multiple users in a single frequency band, so it has high spectral efficiency and energy efficiency. Energy efficient multicast technology is the focus of research in 5 G system in the future. In order to improve the energy efficiency of multicast system, cooperative relay technology is introduced into multicast communication system, called cooperative group broadcast communication. Cooperative group broadcast transmission consists of two stages. In the first stage, the base station broadcasts the same data to all users, which results in a low probability of interruption for users in the center of the cell and a high probability for users at the edge of the cell. In other words, most of the cell center users receive the data successfully, but most of the cell edge users can not receive the data successfully. In the second phase, some successful users relay received data to failed users as relays. By designing an efficient cooperative multicast relay algorithm, the energy efficiency of the multicast system can be effectively improved, thus satisfying the spectral efficiency and energy efficiency leapfrogging of the 5G system. Therefore, this paper mainly studies relay selection and power control algorithms in cooperative group broadcasting. Firstly, a probabilistic double-slot cooperative broadcast relay algorithm is proposed. In this algorithm, the energy efficiency and interrupt probability constraints of multicast system are first modeled as an optimization problem, and then the influence of relay probability and relay power of successful users in the second slot on the optimization expression is analyzed. The relay probability and relay power are obtained under the optimal condition. The simulation results show that compared with the traditional method, our algorithm can achieve higher energy efficiency. Then, the relationship between the outage probability distribution and the relaying energy consumption is studied. We find that the unbalanced outage probability distribution between the cell central user and the cell edge user is the main reason for the waste of relaying power. Considering the characteristics of outage probability and energy efficiency of users in different cell locations, this paper presents a high energy efficiency dual-slot cooperative broadcast relay algorithm. In particular, an optimal interrupt reduction algorithm based on equilibrium is given, and a sub-optimal algorithm based on equilibrium interrupt probability distribution is also found. The computational complexity of the optimal and suboptimal algorithms increases linearly with the increase of the number of samples between the base station and the user. Simulation results show that compared with the traditional algorithm, our algorithm can reduce the user relay power consumption by about 54% and 40% respectively. Finally, we summarize the contributions of the paper and analyze the future research direction.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.5

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