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为了提升星载船舶自动识别系统(AIS)的卫星接收性能,提出了一种采用4 b循环冗余校验(CRC)纠错与迭代干扰消除算法的星载AIS接收方案。针对星载AIS系统中多路信号碰撞明显的情况,首先,通过分析星载AIS系统中CRC错误类型,采用比特反转的方式进行纠错;其次,对纠错后的序列进行AIS数据重构,采用迭代干扰消除方法消除重构信号,并将余下信号作为输入信号再次进入系统进行解调。仿真结果表明,和传统的CRC纠错系统相比,针对典型的两路信号碰撞情况,基于4 b CRC校验与迭代干扰消除的星载AIS系统能够带来1~2 dB的误码率增益,对星载AIS系统的性能提升有重要指导意义。 相似文献
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介绍了国外机载射频系统的组成,分析了机载射频系统的战技指标,探讨了国外试验
外场的设计和设备配备。借鉴国外经验,总结了机载射频系统测试内容,提出针对
机载射频系统地面测试外场建设的新思路,为工程实施奠定基础。 相似文献
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针对现有机载时间同步系统在综合航电系统架构下通用性和可扩展性不足的问题,提出了一种具有开放式特征的机载时间同步系统架构。首先根据机载时间同步系统应用需求,分析了机载平台可选的技术手段,然后围绕时间链路、时间处理、时间管理、时间应用等基本要素,将机载时间同步系统自上而下划分为三个部分,从而形成分层次的机载时间同步架构。该架构在层间采用了标准开放接口,能同时兼容多种机间时间比对链路,具备多时间管理和时间品质评估的能力。最后,介绍了该架构下的时间同步实现流程,并分析了影响同步精度的主要误差环节。桌面测试结果表明,所提架构能够实现优于10 ns的时间同步精度。 相似文献
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内河船舶避碰技术中的自动识别系统(AIS)是一种关键应用,它在船舶航行和避碰中发挥着重要作用。本文旨在通过了解AIS自动避碰系统的基本原理,重点分析内河船舶避碰技术中自动识别系统的应用。首先,AIS利用无线电通信技术,能够探测目标并提供实时的船舶信息,帮助船舶及时了解周围环境,避免碰撞事故的发生。其次,AIS在海上搜寻和救助中发挥重要作用,提供船舶位置和状态信息,协助救援行动。在船舶自动避碰系统中,AIS可通过获取避碰信息,实现船舶的避让行动。因此,自动识别系统的应用可以提升船舶的避碰认知能力,改进海事通信功能,并为避让行动提供可靠保障。 相似文献
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《中国对外贸易(英文版)》2008,(5):50-51
The overall strategic relationship between U.K. and China is "better than ever", China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future. 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(5)
Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit. 相似文献
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《中国对外贸易(英文版)》2008,(6):62-65
Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service & trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,"In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves." 相似文献
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Zang Kejia 《中国对外贸易(英文版)》2008,(7):16-17
When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years' experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year. 相似文献
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Estaing, former French president, Valery Giscard d'Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself"French Confucian", then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually "Partners". 相似文献
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《中国对外贸易(英文版)》2008,(5):12
The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy. 相似文献
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"If you are considering to trade with companies in Japan or expanding your business to Japan we are ready to help from the very beginning."You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization 《中国对外贸易(英文版)》2008,(10):16-17
If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning." You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization (JETRO). JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China's Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING. 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(12):62-63
Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship, 相似文献
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Guo Yan 《中国对外贸易(英文版)》2008,(1):10-10
In the middle of last December, the key purchase contracts for coal used in power generation in 2008 were signed, reflecting a demand for more than 1.085 billion tons. It is important to note that the country's five biggest power producers, China Huaneng Group, China Guodian Corporation, China Power Investment Corporation, China Huadian Corporation and China Datang Corporation, had settled on the prices on their purchase contracts, and they are expected to consume 290 million tons of coal for generating electricity, 相似文献
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Liu Xinwen 《中国对外贸易(英文版)》2008,(7)
Last year,the volume of China's auto trade reached US$66.878 bil- lion,of which imports accounted for US$25.982 billion,a year-on- year increase of 24.45 percent;while ex- ports totaled US$40.896 billion,growing by 45.31 percent.The China Association of Automobile Manufacturers(CAAM) predicts that the number of autos sold in 2008 will break the 1 million barrier for the first time in history,representing an increase of about 20 percent. 相似文献