We consider the problem of target localization by a network of passive sensors. When an unknown target emits an acoustic or a radio signal, its position can be localized with multiple sensors using the time difference of arrival (TDOA) information. In this paper, we consider the maximum likelihood formulation of this target localization problem and provide efficient convex relaxations for this nonconvex optimization problem.We also propose a formulation for robust target localization in the presence of sensor location errors. Two Cramer-Rao bounds are derived corresponding to situations with and without sensor node location errors. Simulation results confirm the efficiency and superior performance of the convex relaxation approach as compared to the existing least squares based approach when large sensor node location errors are present.
标签： 传感器网络
上传时间： 2016-11-27
上传用户：xxmluo
3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Further advancements for E-UTRA; LTE-Advanced feasibility studies in RAN WG4 (Release 9)
上传时间： 2018-04-28
上传用户：doforfuture
Recently millimeter-wave bands have been postu- lated as a means to accommodate the foreseen extreme bandwidth demands in vehicular communications, which result from the dissemination of sensory data to nearby vehicles for enhanced environmental awareness and improved safety level. However, the literature is particularly scarce in regards to principled resource allocation schemes that deal with the challenging radio conditions posed by the high mobility of vehicular scenarios
标签： Communications Millimeter Wave V2V
上传时间： 2020-05-23
上传用户：shancjb
During the past years, there has been a quickly rising interest in radio access tech- nologies for providing mobile as well as nomadic and fixed services for voice, video, and data. The difference in design, implementation, and use between telecom and datacom technologies is also getting more blurred. One example is cellular technologies from the telecom world being used for broadband data and wireless LAN from the datacom world being used for voice over IP.
上传时间： 2020-05-26
上传用户：shancjb
This book provides technical information about all aspects of 3GPP LTE. The areas covered range from basic concepts to research-grade material, including future directions. The book captures the current state of 3GPP LTE technology and serves as a source of comprehensive reference material on this subject. It has a total of 12 chapters authored by 50 experts from around the world. The targeted audi- ence includes professionals who are designers or planners for 3GPP LTE systems, researchers (faculty members and graduate students), and those who would like to learn about this field.
标签： Technology Cellular Radio 3GPP LTE and
上传时间： 2020-05-26
上传用户：shancjb
Duringthe past years, there has been a quickly rising interest in radio access technologies for providing mobile as well as nomadic and fixed services for voice, video, and data. This proves that the difference in design, implementation, and use between telecom and datacom technologies is also becoming more blurred. What used to be a mobile phone used for voice communication is today increasingly becoming the main data communication device for end-users, providing web browsing, social networking, and many other services.
标签： LTELTE-Advanced 4G
上传时间： 2020-05-26
上传用户：shancjb
The surge of mobile data traffic forces network operators to cope with capacity shortage. The deployment of small cells in 5G networks is meant to reduce latency, backhaul traffic and increase radio access capacity. In this context, mobile edge computing technology will be used to manage dedicated cache space in the radio access network. Thus, mobile network operators will be able to provision OTT content providers with new caching services to enhance the quality of experience of their customers on the move.
上传时间： 2020-05-26
上传用户：shancjb
The Internet of Things is considered to be the next big opportunity, and challenge, for the Internet engineering community, users of technology, companies and society as a whole. It involves connecting embedded devices such as sensors, home appliances, weather stations and even toys to Internet Protocol (IP) based networks. The number of IP-enabled embedded devices is increasing rapidly, and although hard to estimate, will surely outnumber the number of personal computers (PCs) and servers in the future. With the advances made over the past decade in microcontroller,low-power radio, battery and microelectronic technology, the trend in the industry is for smart embedded devices (called smart objects) to become IP-enabled, and an integral part of the latest services on the Internet. These services are no longer cyber, just including data created by humans, but are to become very connected to the physical world around us by including sensor data, the monitoring and control of machines, and other kinds of physical context. We call this latest frontier of the Internet, consisting of wireless low-power embedded devices, the Wireless Embedded Internet. Applications that this new frontier of the Internet enable are critical to the sustainability, efficiency and safety of society and include home and building automation, healthcare, energy efficiency, smart grids and environmental monitoring to name just a few.
标签： Embedded Internet Wireless 6LoWPAN The
上传时间： 2020-05-26
上传用户：shancjb
The current methods of communications are becoming less relevant under today’s growing demand for and reliance on constant connectivity. Of decreasing relevance are the models of a single radio to perform a single task. The expansion of wireless access points among coffee shops, airports, malls, and other public arenas is opening up opportunities for new services and applications.
上传时间： 2020-05-26
上传用户：shancjb
Wireless penetration has witnessed explosive growth over the last two decades. Accordingly, wireless devices have become much denser per unit area, resulting in an overcrowded usage of wireless resources. To avoid radio interferences and packet collisions, wireless stations have to exchange control messages to coordinate well. The existing wisdoms of conveying control messages could be classified into three categories: explicit, implicit, or hybrid.
标签： Transmission Attachment Networks Wireless in
上传时间： 2020-05-26
上传用户：shancjb
