基于分布式天线系统的协作通信关键技术研究

发布时间：2018-03-08 23:32

本文选题：分布式天线系统　切入点：协作通信　出处：《南京邮电大学》2017年硕士论文　论文类型：学位论文

【摘要】：为了满足人们日常对无线多媒体通信业务不断增加的需要,下一代无线通信系统急需提供更高的传输速率和更可靠的传输性能。未来无线通信网络必将是一个异构通信网络,支持多种无线网络的融合。与传统蜂窝小区相比,在分布式天线系统中引入协作传输,不仅可以获得多径传输和多天线的性能增益,而且可以有效降低移动终端的发射功率和阻塞概率,显著提升无线网络的综合传输性能,这方面的研究正受到越来越多的关注。论文主要研究了协作通信中节点的联合发射功率分配问题和基于分布式天线系统的多用户传输策略问题。首先,从协作中继基本原理的角度出发,详细介绍采用两种基本中继转发协议的几种协作通信系统模型。不管是固定中继的协作通信(协作MIMO)还是用户终端间的协作通信(多用户协作),它们的协作通信模型本质上都是相同的。因为在无线通信系统中,各个天线节点和用户终端都可以作为潜在的中继节点,所以这里只考虑怎样合理分配功率以满足某一个或几个有效的系统性能指标。接着,论文从能耗和性能的问题考虑,分别给出了基于单用户传输信息的单中继和多中继的功率分配方法。采用直接计算法分析单中继系统,利用拉格朗日乘子算出最优分配解;对多中继系统,利用拉格朗日乘子并结合最陡下降法给出最优分配解的集合。而后分别对单中继、多中继系统的等功率分配和最优功率分配进行仿真,并通过仿真结果验证了协作传输能够有效地改善了系统性能。最后,对基于分布式天线系统的协作通信进行研究。在分布式天线网络中,依靠分布式天线进行通信,可以有效减小网络覆盖盲区以及显著提高小区边缘用户的传输速率。但当小区用户通信活跃时,显然分布式天线不能满足大多数用户的通信需求,而且由于用户都有通信需求,多用户协作就很难开展。因此,论文介绍了一种基于谈判能力的自组织组队协作传输策略,仿真结果表明,对于相距较近的两用户,组队协作可以使双方获得即时的性能增益。
[Abstract]:In order to meet the daily increasing demand of wireless multimedia communication services, the next generation wireless communication system urgently needs to provide higher transmission rate and more reliable transmission performance. In the future, wireless communication network will be a heterogeneous communication network. Compared with traditional cellular cell, cooperative transmission is introduced in distributed antenna system, which can not only achieve multi-path transmission and multi-antenna performance gain, but also support multi-wireless network fusion. Moreover, it can effectively reduce the transmission power and blocking probability of the mobile terminal, and significantly improve the comprehensive transmission performance of the wireless network. In this paper, the joint transmit power allocation of nodes and the multi-user transmission strategy based on distributed antenna system are studied. From the point of view of the basic principle of cooperative relay, Several kinds of cooperative communication system models using two basic relay forwarding protocols are introduced in detail. Whether they are fixed relay cooperative communication (cooperative MIMOO) or cooperative communication between user terminals (multi-user cooperative communication), their cooperative communication is introduced in detail. The models are essentially the same because in wireless communication systems, Each antenna node and user terminal can be used as potential relay nodes, so we only consider how to allocate power reasonably to satisfy one or more effective system performance indicators. The power allocation methods of single relay and multi relay based on single user transmission information are given respectively. The direct calculation method is used to analyze the single relay system, and the Lagrange multiplier is used to calculate the optimal allocation solution. The set of optimal allocation solutions is given by Lagrange multiplier and steepest descent method. Then the equal-power allocation and optimal power allocation of single-relay and multi-relay systems are simulated respectively. The simulation results show that cooperative transmission can effectively improve the performance of the system. Finally, the cooperative communication based on distributed antenna system is studied. It can effectively reduce the blind area of the network and significantly improve the transmission rate of the cell edge users. But when the cell users communicate actively, it is obvious that the distributed antenna can not meet the communication needs of most users, and because the users have communication needs, Therefore, a self-organizing cooperative transmission strategy based on negotiation ability is introduced in this paper. The simulation results show that for the two users who are close to each other, the team collaboration can achieve real-time performance gains.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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