Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract: Underwater acoustic communication is a key technology in the field of underwater activities including underwater surveillance, underwater operations, and military actions. The complexity of the underwater communication channel strongly restricts underwater communication speed, distance, and reliability. Incoherent communication is more robust to channel variation and is wildly used today. Coherent communication is ten times faster than incoherent communication. But it is more vulnerable to channel variation. It is still under developing. To further improve underwater communication performance, the community is keeping improving adaptive equalization algorithms, error correction coding, etc., and developing new technologies like time reversal technology, MIMO technology, etc. Many Chinese organizations joined in the development of underwater communication and networking technology. They carried out theoretical researching, prototypes building, lake and sea trials, and achieved much progress. Especially in last fifteen years, with enhanced support from Chinese government funding, China shortened the gap in underwater communication and networking technology between the leading counties in the world but still at least five years behind them in both theory research and commercial product development. China needs to keep working hard in all fields of underwater communication including algorithm research, networking protocol design, more lake and sea trials, more application, hardware developing and commercial products developing.
Subjects: Computer Science >> Computer Application Technology submitted time 2017-03-10
Abstract:有限的无线资源与不断增长的无线业务需求成为越来越突出的矛盾。怎样进一步提高频谱使用效率已成为未来无线技术研究的重要课题。受频谱资源以及独立优化架构的限制,现有的无线网络将很难进一步提高空中接口的频谱效率和网络的整体性能。为从根本上提高无线频谱利用的效率,需要使网络中的各元素进行智能协作,从而达到网络资源共享、提高传输可靠性和系统吞吐量、有效改善用户服务质量。这 就是先进无线协作通信技术。本文对无线协作通信技术进行了较系统的总结和介绍。
Peer Review Status:Awaiting Review
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract:在广播电视卫星通信中,无线电通信技术属于重要保障。以当前广播电视卫星通信发展为依据,联合无线电通信技术应用特点,确定广播电视通信干扰,深入分析无线电通信技术对广播电视卫星通信的影响,明确无线电通信技术未来发展趋势,从根本上促进广播电视产业发展。本文主要讨论和探究无线电通信技术对广播电视卫星通信的影响,以供参考。
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract:在当今网络信息快速发展的时代,网络通信已经遍布多个社会领域中,对于社会发展的推动和人们日常生活的便捷起到了重要的作用。计算机网络具有互联性、开放性、分布不均匀性等特点和在其它技术的缺陷,使网络通信安全的事件频繁发生,用户使用受到严重影响。对人们在网络活动上的保密性要求也越来越高,应用数据加密技术,保证了人们在网络活动中对自己的数据和一些相关资料保密的要求,保证了网络的安全性和保密性。
Subjects: Computer Science >> Computer Network submitted time 2016-11-02
Abstract:千万亿次规模系统中,互连网络设计面临新的挑战。结点性能不断提高和系统规模持续扩大是构建千万亿次系统的主要技术趋势,不断提高的结点计算能力要求互连网络提供更高的性能,而不断增大的规模又对互连网络扩展性提出了更高的要求。此外,随着系统规模的增大,集合通信的执行时间也在不断增长,制约了应用的扩展性,集合通信的性能需要进一步优化。针对上述问题,本文从互连网络体系结构、网络接口控制器设计、交换机结构设计和集合通信性能优化等几个方面,对互连网络设计方法进行研究,提出了曙光5000 高性能互连网络的设计思想。测试及模拟结果表明,曙光5000 互连网络在单播、多播和栅障同步(Barrier)通信方面均可获得较高的性能。
Peer Review Status:Awaiting Review
Subjects: Engineering and technical science >> Metrology Subjects: Engineering and technical science >> Technology of Instrument and Meter submitted time 2024-03-28
Abstract: The research of smart meter communication technology is an important research direction in the field of electric power, which involves in-depth exploration and technological innovation of smart meter communication system. With the development of smart grid, smart meter, as a key information interaction node between the power grid and users, the research and application of communication technology is of great significance for improving the intelligence level of the power grid and optimizing the allocation of power resources. The study includes the evaluation and improvement of existing communication technologies to meet the specific needs of smart meter communication. For example, narrowband and broadband power line carrier communication is a technical direction that can lead the research and application of the meter industry, and its progress in maintenance-free technology, automatic debugging terminal, automatic networking instrument and other aspects are all hot spots in current research. At the same time, the research and optimization of long-range wireless communication systems and the research and development of intelligent terminals are also important aspects of the research of smart meter communication technology. In addition, the research of smart meter communication technology also needs to pay attention to communication protocols, communication security, data processing and other issues. By formulating a unified communication protocol, the interconnection between different devices can be realized, and the compatibility and scalability of the system can be improved. At the same time, strengthening the research on communication security can ensure the safe transmission of power data and prevent data leakage and illegal access. In terms of data processing, through the use of advanced data analysis technology, power data can be deeply mined, providing strong support for decision-making and operation in the power industry. In general, the research of smart meter communication technology is a comprehensive research topic involving many fields, and it is necessary to continuously track the development of new technologies, and carry out technological innovation and application promotion in combination with actual needs to promote the intelligent development of the power industry.
Peer Review Status:Awaiting Review
Subjects: Astronomy submitted time 2018-12-04 Cooperative journals: 《天文研究与技术》
Abstract:观测控制系统(Observation Control System,OCS)是当前的一个研究热点,底层通信是OCS架构中重要的一个环节。但传统的OCS中一般采用裸套接技术实现,缺少统一的传输控制机制,在密集数据通信时经常存在延迟影响实时控制的需要; 同时缺少广播与组播机制,限制了OCS系统的设计。本文针对OCS的要求,系统研究分析了基于ZeroMQ不同通信模型及所对应的天文控制模式,对不同的通信控制架构可用性进行了分析。在此基础上通过实验对相应的通信模型进行了测试,验证其在天文仪器分布控制中的可用性。测试结果进一步说明ZeroMQ构建OCS的底层通信架构是可行的,能够满足OCS对设备的各种控制需求。
Subjects: Geosciences >> Space Physics submitted time 2016-04-22
Abstract: In order to ensure the success of space exploration mission, the small satellite formation requires reliable inter-satellite communications. Based on 802.11, small satellite formation network protocol architecture was designed. Firstly, network protocol stack was built according the OSI stack layers, the key parameters of physical layer and data link layer of was tuned to meet the requirement of inter-satellite communication, the network layer routing protocol was analysed, and then the satellite network formation model was made and analysed. With the aid of the network simulation tool NS3, performance of four typical formation network was simulated. Simulation results show that the network protocol architecture ensures inter-satellite communications based on 802.11. Although network performance varies greatly in different flyning formations, it can be adjusted according to the task requirements.
Peer Review Status:Awaiting Review
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract:近些年来,随着国家广播电视数字化进程和三网融合的不断推进,广电物联网通信的发展如火如荼。本文通过分析广电物联网通信发展现状,对广电物联网通信应用进行了研究,并从广电网的特点和优势出发提出了一些推动广电物联网通信发展的措施,以期能够为相关工作提供一些帮助,从而促进广电事业的不断发展。
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract: A new bi-phase modulation (BPM) pulse UWB transmitter manufactured by discrete components is designed. The transmitter consists of mono-polar sub-nanosecond pulse generator, bipolar pulse generator,and high speed microwave switch. The transmitter transmit positive and negative pulses when controlled by clock signal as well as data ' 1' and data ' 0',respectively. Experimental results show that the generated pulse width is below 400 ps,the bandwidth is more than 1. 5 GHz,and the data rate is up to 50 Mbps. It can be used in the pulse UWB (ultrawideband) communication systems.
Peer Review Status:Awaiting Review
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2022-04-07 Cooperative journals: 《计算机应用研究》
Abstract: Age of Information (AoI) is a performance metric that captures the freshness of data from the destination’s perspective. In the energy constrained real-time sensing Internet of things scenario, this paper proposed a joint sampling and hybrid backscatter communication updating policy to improve the AoI performance of the system. The policy minimized the long-term average AoI of the system by allowing the source to select state sampling actions and transmission modes of updating processes. Specifically, this paper modeled the problem as an average cost Markov decision process (MDP) . Then, when the system realized the dynamic environment information, the paper adopted optimal strategy by relative value iterative algorithm. When the system lacked the dynamic environment information, the paper applied Q-learning algorithm and exploration exploitation technique to learn the optimal strategy through trial-and-error interactions with the environment. Simulation results show that compared with the two reference policies, the proposed policy significantly improves the AoI performance of the system, and the AoI performance of the system increases with the decrease of the update package size or the increase of battery capacity.
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-07 Cooperative journals: 《分子影像学杂志》
Abstract: Objective To reduce the difficuty and cost incurred to small and medium sized hospitals in their construction of PACS system. Methods Based on SaaS model incorporated with cloud algorithms, Cloud PACS was proposed of which cloud PACS was designed in three parts: cloud displaying, cloud flow chart and cloud doc-filing. Results Flexible use of cloud PACS was believed to be capable of reducing both the cycles and costs caused by small and medium sized hospitals in main tenance of PACS construction. Conclusion Cloud algorithms based PACS is believed to represent The development of new generation of PACS, a forthcoming new guideline for small and medium sized hospitals, regional medical treatment and group hospitalsin building up their PACS
Subjects: Computer Science >> Computer Application Technology submitted time 2016-05-04
Abstract:随着云计算的发展,数据中心快速崛起并给设计者和管理者带来了很多新的挑战。模拟作为一种研究
Peer Review Status:Awaiting Review
Subjects: Engineering and technical science >> Metrology Subjects: Engineering and technical science >> Technology of Instrument and Meter Subjects: Energy Science >> Survey of Energy Sources submitted time 2024-01-29
Abstract: This paper mainly introduces the remote automatic meter reading system technology of the State Grid in the early 90s of the 20th century, and with the introduction of electronic meters and smart meters, the local and remote communication technology has been rapidly updated, which has promoted the development of remote automatic meter reading system technology. From 2010 to 2018, the State Grid carried out the large-scale construction of the provincial power grid electricity information collection system, and invested a lot of money in the construction of collection equipment and user projects. By the end of 2018, the number of smart meters operated by the State Grid reached 458 million, and the user coverage rate of the electricity information collection system reached 99.87%. In the area of communication technology, the text refers to the development of local and remote communication methods. The local communication mode has undergone the evolution from narrowband powerline carrier communication technology to broadband powerline carrier communication technology, while the long-distance communication mode has successively adopted GPRS and 4G public network wireless communication. This paper also introduces the origin, development and gradual fading out of the market of narrowband CLC technology, as well as the rise and development of broadband CLC technology.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2020-08-14 Cooperative journals: 《天文研究与技术》
Abstract:随着天文技术的不断发展,远程观测和自主观测逐渐成为天文观测的主流趋势,自动调焦技术也越来越受到重视。电动调焦器是天文望远镜不可或缺的附属设备,是实现自动调焦的关键设备。为实现云南天文台丽江天文观测站10英寸米德望远镜的自动调焦,自行研发了一套天文电动调焦器,设计相关控制电路,制定串口通信协议,并编写了一套开源ASCOM驱动程序SS Focuser。本文详细介绍了该电动调焦器的结构原理和实现方法,实测结果表明具有很好的稳定性,完全满足设计要求,为天文电动调焦器设计提供了可借鉴的经验和方法。
Subjects: Astronomy >> Astrophysical processes submitted time 2018-05-29 Cooperative journals: 《天文研究与技术》
Abstract: FocusGEO是上海天文台自行研制的新一代地球同步轨道动态监视系统,与大部分商用成熟的天文望远镜相比缺乏标准的硬件底层驱动,同时受到运行环境限制,无法设计开发基于Linux的RTS2或基于Windows的ASCOM的全自动化软件系统。研究团队针对FocusGEO的特殊需求,自行设计开发了一套基于Windows的软件系统,可实现望远镜自动观测、资料实时处理、数据传输与数据管理等过程。介绍了软件系统的实现框架、整体流程和数据并行处理的原理,并重点讨论图像实时转换与传输和数据实时处理与入库的实现方法。长时间的观测运行表明,软件系统工作稳定可靠,可为非通用望远镜系统的自动控制软件开发提供借鉴。
Subjects: Computer Science >> Computer Network submitted time 2017-03-10
Abstract:本文提出了一套面向行业应用的宽带无线通信系统解决方案,对该方案的网络架构、各功能部件 及采用的关键技术进行详细阐述,并对该网络系统的典型应用场景和目前针对该方案已取得的研发成果和 下一步研发部署进行介绍。
Peer Review Status:Awaiting Review
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract:本文对2021年互联网、通信行业、电视媒体等广电相关行业的发展状况进行了梳理、分析,提出了未来网络云网融合、服务定制网络、IPv6加速部署、网络可编程语言、可信网络的发展趋势。
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract:移动通信技术的发展深刻改变传统广电媒体的格局,本文介绍了移动通信技术的发展和对广电媒体的影响,以及广电媒体在应对这场变革的一些做法和实践。
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-08-13 Cooperative journals: 《计算机应用研究》
Abstract: In view of the complexity of fast and time-varying wireless communication in vehicle-to-vehicle communication and the complexity of the tracking, the channel estimation scheme based on the preamble in the IEEE802.11a system cannot meet the requirements in the high-speed scene. This paper proposed a decision feedback channel estimation method based on blind channel estimation. With the help of output decision symbols from the receiver demodulator, the fast changing channel transfer function is tracked using the statistical characteristics of the data transmitted by the noise fading channel. The time truncation technique uses the decision feedback to reduce the noise influence, eliminate the inter carrier interference and improve the estimation accuracy of the fast time-varying channel. Simulation results show that the proposed algorithm has better BER and MSE performance than these classical channel estimation algorithms.