High-Density Random Access for High-Speed Satellite Data Services

高速卫星数据服务的高密度随机接入

• 批准号: RGPIN-2015-04931
• 负责人: Schlegel, Christian
• 金额: $ 1.82万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=680750
• 关键词: Density; Random; Access; Speed; Satellite

In recent years there has been a strong resurgence in interest in satellite communications. The European Space Agency (ESA), for example is investigating satellite-based wireless data services using multi-spot, high-capacity geo-stationary satellites. Such a system will require a satellite throughput capacity on the order of a terabyte/s in order to be economically competitive with ground-based wireless services. ***A modern satellite, operating with multiple spot beams, is capable of covering a large geographic area and servicing a very large number of users. Difficulties arise when the traffic through the satellite increases to the point where basic access and communications methods no longer suffice to service the data demand. This difficulty is compounded by the long round-trip delays between transmissions on the up-link and reception of acknowledgements on the down-link, which prevents rapid coordination between transmitters. The receiver also needs to be able to resolve signal collisions and be able to estimate and track channel conditions for a multitude of user terminals. These challenges represent a are the major focus of the proposed research project.***The most recent variations of random access contention resolution transmit multiple copies of a data packet in randomly distributed time slots throughout a transmission frame. This approach statistically increases the rate of packet collisions, but the probability that at least one copy of a packet is received collision-free is increased. This packet can then be cancelled from the other time slots where it was also transmitted, allowing for iterative peel-off decoding of the entire frame. Theoretical studies have shown that this method can achieve 80% of the single user capacity for practical scenarios, which represents a vast improvement over the 37% achievable with a basic slotted ALOHA protocol. ***However, the channel itself, is a multiple access channel, and as such it has a theoretical capacity which is superior to that of any multiplexed channel. Exploitation of this advantage requires the incorporation of joint detection principles. Multi-packet reception(MPR) will be addressed with iterative interference cancellation, which has recently been shown to be able to approach the multiple access channel capacity in theory. However, substantial problems remain before such MPR receivers can be deployed. This project focuses on the challenges that arise when realistic channel propagation models are used, in particular channels with highly dynamic behavior. It is anticipated that the fundamental results from this work will lead to increased utilization of spectral resources and robustness of networks. We have been collaborating with the German Aerospace Institute (DLR), and this grant will accelerate this collaboration, and lead to a strong research program in resource-efficient data communications at Dalhousie University.**

近年来，人们对卫星通信的兴趣充满了兴趣。例如，欧洲航天局（ESA）正在使用多点，大容量的地理层面卫星研究基于卫星的无线数据服务。这样的系统将需要按照trabyte的顺序获得卫星吞吐量，以便在经济上与地面无线服务具有竞争力。 ***现代卫星，具有多个斑点梁，它能够覆盖较大的地理区域并为大量用户提供服务。当通过卫星的流量增加到基本访问和通信方法不足以满足数据需求的基本访问和通信方法时，就会出现困难。这一难度是由于在上链接上的传输和接收到下链路上的确认，从而阻止了发射器之间的快速协调。接收器还需要能够解决信号碰撞，并能够估算和跟踪多种用户终端的通道条件。这些挑战代表了拟议的研究项目的重点。从统计学上讲，这种方法可提高数据包碰撞的速率，但是至少收到包数据包的副本的概率增加了。然后可以从其他时插槽中取消此数据包，在该插槽中也可以传输，从而允许整个帧的迭代剥离解码。理论研究表明，该方法可以实现单个用户的实用情景能力的80％，这代表了通过基本的插入ALOHA协议实现的37％的巨大改善。 ***但是，通道本身是一个多访问通道，因此它具有优于任何多重通道的理论能力。对此优势的开发需要继承检测原则。多包装接收（MPR）将通过迭代干扰取消来解决，最近已证明它能够在理论上接近多个访问通道容量。但是，在部署此类MPR接收器之前仍然存在实质性问题。该项目着重于使用现实的渠道传播模型时出现的挑战，特别是具有高度动态行为的渠道。预计这项工作的基本结果将导致频谱资源和网络鲁棒性的利用增加。我们一直在与德国航空航天学院（DLR）合作，这笔赠款将加速这一合作，并在达尔豪西大学（Dalhousie University）进行了强大的资源效率数据通信研究计划。**