面向无线网络的中继协助传输研究

发布时间：2019-02-13 13:07

【摘要】：随着通信技术的迅猛发展,飞速膨胀量成了下一代无线网络中最关键的问题。而中继以其性能佳、易于拓展部署方便等优势在新一代网络标准中占有一席之地。本文挑选了三个典型的场景-WiMAX,数据中心网络和蜂窝网络-作为中继性能研究的承载场景。对于目前采用多跳中继技术的WiMAX网络,本文提出DPRP (Dual-Path Relay Placement)以优化中继的布局。DPRP通过两条平行对称的多跳中继链路获得空间复用。对于给定的衰减因子,当用户的频谱效率超过一定界限时,相比SPRP (Single-Path Relay Placement)策略DPRP更加节省中继。分析得知,用户的频谱效率越高,DPRP的优势就越明显。对单个蜂窝而言,如果将SPRP和DPRP结合使用,必将大大降低中继带来的开销。数据中心网络布线复杂且开销较大,促使人们引入无线中继来缓解机架的拥塞问题。研究者在无线数据中心领域已取得很多成果,但目前为止还没人将目光锁定在功率分配问题上。所以本文便提出动态的功率分配策略,该策略简单易行,并且可以大大提升无线数据中心网络的吞吐量。仿真结果也很好地验证了动态功率策略的确优于传统的等功率发送策略。在蜂窝网络中,数据流量的合理管理越来越受重视。存在的首要问题是一部分用户流量不够用,另一部分却用不完。基于此本文设计出一个协助传输系统以优化所有用户的体验,前提假设是具有剩余流量的用户愿意协助其余用户下载一些东西,然后将下载的数据通过WiFi重传给请求用户。为了保证系统的实现,第一步提出一个基于LT码的UDP协议,该协议可以保证协助的正常进行；接下来设计了一个实际系统来进行验证,结果表明用户可以更有效地管理自己的数据,而且还可以大大提升自己的下载速率。
[Abstract]:With the rapid development of communication technology, rapid expansion has become the most critical problem in the next generation wireless network. Relay has the advantages of good performance, easy to expand and easy to deploy in the new generation of network standards. In this paper, three typical scenarios-WiMAX, data center network and cellular network-are selected as carrying scenarios for relay performance research. For the current WiMAX network using multi-hop relay technology, DPRP (Dual-Path Relay Placement) is proposed to optimize the relay layout. DPRP achieves spatial multiplexing through two parallel symmetric multi-hop relay links. For a given attenuation factor, when the user's spectral efficiency exceeds a certain limit, the relay is more efficient than SPRP (Single-Path Relay Placement) DPRP). The analysis shows that the higher the spectrum efficiency of the user, the more obvious the advantage of DPRP. For a single cell, if the combination of SPRP and DPRP is used, the overhead of relay will be greatly reduced. Data center network routing is complicated and expensive, which urges people to introduce wireless relay to alleviate the congestion problem of frame. Researchers have made a lot of achievements in wireless data centers, but so far no one has focused on power allocation. Therefore, this paper proposes a dynamic power allocation strategy, which is simple and easy to implement, and can greatly improve the throughput of wireless data center network. The simulation results show that the dynamic power strategy is indeed superior to the traditional equal-power transmission strategy. In cellular networks, more and more attention is paid to the rational management of data traffic. The first problem is that part of the user flow is not enough, but the other part is not exhausted. Based on this, an assisted transmission system is designed to optimize the experience of all users. The premise is that users with residual traffic are willing to assist other users to download something, and then transfer the downloaded data to the requesting user through WiFi. In order to ensure the implementation of the system, the first step is to propose a UDP protocol based on LT code, which can ensure the normal operation of the assistance. Then a practical system is designed to verify that users can manage their own data more effectively and can greatly improve their download rate.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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