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重新浓厚，例如，欧洲航天局 (ESA) 正在研究使用多点、大容量地球静止卫星的卫星无线数据服务。需要 TB/s 量级的卫星吞吐量，才能在经济上与地面无线服务竞争***采用多个点波束运行的现代卫星能够覆盖较大的地理区域并提供服务。当通过卫星的流量增加到基本接入和通信方法不再足以满足数据需求时，就会出现大量的困难，而上行传输之间的长往返延迟会加剧这种困难。 -下行链路上的确认接收，这阻碍了发射机之间的快速协调。接收器还需要能够解决信号冲突并能够估计和跟踪多个用户终端的信道状况。挑战是所提出的研究项目的主要焦点。***随机访问争用解决方案的最新变化在整个传输帧中的随机分布的时隙中传输数据包的多个副本。这种方法特别提高了数据包的速率。冲突，但至少一个数据包的副本被无冲突地接收的概率会增加，然后可以从也传输该数据包的其他时隙中取消该数据包，从而允许对整个帧进行迭代剥离解码。理论研究表明，这种方法可以实现实际单用户容量的 80%，这比基本时隙 ALOHA 协议可实现的 37% 有了巨大的改进***但是，信道本身的场景是多址接入。信道，因此它的理论容量优于任何复用信道。要利用这一优势，需要结合多数据包接收（MPR）原则。最近已被证明能够在理论上接近多址信道容量。然而，在部署此类 MPR 接收器之前仍然存在大量问题，该项目重点关注实际信道传播模型时出现的挑战。预计这项工作的基本结果将提高频谱资源的利用率和网络的稳健性。 (DLR)，这笔赠款将加速这一合作，并在达尔豪斯大学促成一个强大的资源高效型数据通信研究项目。**