In modern LEO satellite communication systems,numerous singnals have to be located in a same frequency band because of limited spectrum resources.Thus,a bandwidth-efficient modulation,which has constant envelope characteristics and can alleviate signal distortions when using saturated power amplifiers is necessary to combine several signals to share the frequency resource.This paper presents the analytic interplex modulation expression in LEO satellite spread spectrum communication systems,and obtains the relationship of modulation efficiency,error rate and power ratio.Lastly,the appropriate choice of power radio is obtained in the case of three signals or four signals multiplexing.The work of this paper is an important guideline for constant envelope combined methodologies in LEO satellite spread spectrum communication systems.

关键词：通信；恒包络；互复用；调制效率；卫星通信

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As demand for higher data-rate wireless communications increases, so will the interest in multiple-input and multiple-output (MIMO) systems. In a single transmitter, single receiver communication system, there is a fundamental limit to the data-rate capacity of the system proportional to the systems bandwidth. Since increasing the bandwidth is expensive and limited, another option is increasing the systems capacity by adding multiple antennas at the transmitter and receiver to create a MIMO communication system. With a T transmitter, R receiver MIMO communication system, TR channels are created which allow extremely high data-rates. MIMO systems are attractive because they are extremely robust as they are able to operate when encountering channels with severe attenuation also known as deep fades. MIMO systems are known for their ability to achieve extremely high data-rates created by the multiple channels while improving bit error rate (BER) through diversity.

关键词：通信；无线通信；飞船；MIMO；无线电接收机

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This study investigates the adequacy of existing mobility models in capturing various aspects of human mobility behavior (including communal behavior), as well as network protocol performance. This is achieved systematically through the introduction of a framework that includes a multi-dimensional mobility metric space. We then introduce COBRA, a new mobility model capable of spanning the mobility metric space to match realistic traces. A methodical analysis using a range of protocol (epidemic, spraywait, Prophet, and Bubble Rap) dependent and independent metrics (modularity) of various mobility models (SMOOTH and TVC) and traces (university campuses, and theme parks) is done. Our results indicate significant gaps in several metric dimensions between real traces and existing mobility models. Our findings show that COBRA matches communal aspect and realistic protocol performance, reducing the overhead gap (w.r.t existing models) from 80to less than 12, showing the efficacy of our framework.

关键词：通信；计算机网络；流动性；通信协议；无线电线路

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The Department of Commerce's National Telecommunications and Information Administration (NTIA) led an interagency group to determine the viability of accommodating commercial wireless broadband in the 1755-1850 MHz band. While the analyses summarized in this report indicates there are a number of challenges to repurposing, NTIA concludes that it is possible to repurpose all 95 megahertz of the band. This analysis results from an eight-month evaluation process led by NTIA and engaging, via the Policy and Plans Steering Group (PPSG), the predominant federal agency users of this band. Each federal agency analyzed and documented its ability to relocate systems, associated costs, and anticipated periods of transition. In conducting the analysis, NTIA and the federal agencies endeavored to protect critical federal operations from disruption and to reach comparable capability via other spectrum, commercial services, or means that do not utilize spectrum, where appropriate.

关键词：通信；无线通信系统；宽带；可行性分析

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Recently, a real-world haptics which transmits a haptic sensation in real-world has been actively researched. Conventional research of real-world haptics often used low-degree of freedom system. However to transmit human-like haptic information, multi-degrees of freedom robot should be used. On the other hand, general hand robot as multi-degrees of freedom robot often used force sensor. The force sensor can not get the force information which is applied from other points. Therefore, in this research, bilateral control is applied to chain-driven hand robot. Bilateral control based on disturbance observer and reaction force observer can obtain all force information which is applied to robot. The chain-driven robot has some friction and backlash because of chain and gear. These causes of degradation haptic transmission. Thus, in this research, haptic sensation is transmitted by chained driven hand robot. Then, it is analyzed how haptic information the chain-driven robot transits by using transmissibility. Transmissibility is calculated by experiment.

关键词：光机电；机器人；传播能力；双向控制

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We conducted a vehicle analysis to assess the feasibility of thermoelectric technology for waste heat recovery and conversion to useful electrical power and found that eliminating the 500 W of electrical power generated by the alternator corresponded to about a 7increase in fuel economy (FE) for a small car and about 6for a full size truck. Electric power targets of 300 W were established for city and highway driving cycles for this project. We obtained critical vehicle level information for these driving cycles that enabled a highlevel design and performance analysis of radiator and exhaust gas thermoelectric subsystems for several potential vehicle platforms, and we identified the location and geometric envelopes of the radiator and exhaust gas thermoelectric subsystems. Based on this analysis, we selected the Chevrolet Suburban as the most suitable demonstration vehicle for this project. Our modeling and thermal analysis assessment of a radiator-based thermoelectric generator (TEG), however, revealed severe practical limitations.

关键词：新能源与高效节能；余热回收；电力废气；燃油经济性；绩效评价

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In disadvantaged grids, communication resources are scarce and variable. Thus, it is important that middleware and applications are able to adapt to the available capacity. This means that knowledge of the networking environment the C2 software is operating in is of great importance. Monitoring of networks carrying data is important in improving quality of service. There are two main types of monitoring: monitoring in the planning phase; and monitoring during deployment. Here, it is important to know the current load (e.g., link utilization) to be able to shape and control data traffic in a coherent manner. There exist many solutions capable of doing this, but they are mostly geared towards use on the Internet and in corporate networks. Sending data to and from mobile units, like military vehicles moving in a combat zone, provides challenges that may make some current tools unsuitable. In this paper, we focus on freely available tools, and attempt to identify which tools are suitable for the planning phase and which are suitable for the deployment phase in disadvantaged grids.

关键词：通信；带宽；指挥与控制系统；通信协议

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Motor operates as the power source of the vehicles,which is one of the most important parts in the vehicle system.This paper is going to find out the speed control method of the DC motor of Golf electrical cars from both theory and practice.A virtual instrument,which produces the Pulse Width Modulation (PWM) signal,is developed with LabVIEW to control the motor speed.This smart motor speed controller differs from the traditional mechanical control of DC motor in daily life,and is instructive and significant as a new speed control method of vehicle motor.

关键词：新能源汽车；控制器；电机；速度控制器

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This paper provides a framework that can be used to develop technical assistance tools to help employers (including government contractors) design, purchase, lease, maintain and use ICT that is accessible to and usable by people with disabilities and others. More specifically, the Framework can be used as a tool for self-assessment to make easy point-by-point comparisons with current strategies and practices. In addition, the Framework can help a company develop a corporate-wide, comprehensive strategic plan (affirmative action program, where applicable) for adopting and implementing accessible ICT policies, practices and procedures for assessing progress made over time and ensuring continuous improvement. Further, the Framework can be used as a tool for internal staff development and training. In addition to the Framework, the paper also includes a comprehensive Benchmarking Tool, located in the Appendix, which companies could use to conduct a self-assessment and create their own corporate-wide, comprehensive strategic plan (affirmative action program, where applicable), including accountability mechanisms and methods for ensuring continuous improvement. This Benchmarking Tool is organized in accordance with the key components of an Accessible ICT Strategic Plan.

关键词：通信；工作主动性；访问技术；ICT；框架

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The importance of Unmanned Ground Vehicles (UGV's) in the Military's operations is continually increasing. All Military branches now rely on advanced robotic technologies to aid in their missions' operations. The integration of these technologies has not only enhanced capabilities, but has increased personnel safety by generating larger standoff distances. Currently most UGV's are deployed by an exposed dismounted Warfighter because the Military possess a limited capability to do so remotely and can only deploy a single UGV. This paper explains the conceptual development of a novel approach to remotely deploy and extract multiple robots from a single host platform. The Robotic Deployment & Extraction System (ROBODEXS) is a result of our development research to improve marsupial robotic deployment at safe standoff distances. The presented solution is modular and scalable, having the ability to deploy anywhere from two to twenty robots from a single deployment mechanism. For larger carrier platforms, multiple sets of ROBODEXS modules may be integrated for deployment and extraction of even greater numbers of robots. Such a system allows mass deployment and extraction from a single manned/unmanned vehicle, which is not currently possible with other deployment systems.

关键词：光机电；机器人；军队人员；部署提取；集成系统

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