Abstract—In the future communication applications, users may obtain their messages that have different importance levels distributively from several available sources, such as distributed storage or even devices belonging to other users. This scenario is the best modeled by the multilevel diversity coding systems (MDCS). To achieve perfect (information-theoretic) secrecy against wiretap channels, this paper investigates the fundamental limits on the secure rate region of the asymmetric MDCS (AMDCS), which include the symmetric case as a special case. Threshold perfect secrecy is added to the AMDCS model. The eavesdropper may have access to any one but not more than one subset of the channels but know nothing about the sources, as long as the size of the subset is not above the security level. The question of whether superposition (source separation) coding is optimal for such an AMDCS with threshold perfect secrecy is answered. A class of secure AMDCS (S-AMDCS) with an arbitrary number of encoders is solved, and it is shown that linear codes are optimal for this class of instances. However, in contrast with the secure symmetric MDCS, superposition is shown to be not optimal for S-AMDCS in general. In addition, necessary conditions on the existence of a secrecy key are determined as a design guideline.
标签： Fundamental Limits Secure Class on of
上传时间： 2020-01-04
上传用户：kddlas
参考文献：M.Rostami Shahrbabak and H.Nezamabadi-pour, " A New Approach to Binary PSO Algorithm" 14th Iranian Conference on Electrical Engineering, may 2006.
上传时间： 2020-02-16
上传用户：Emperor翔
In the hit CBS crime show Person of Interest, which debuted in 2011, the two heroes—one a former Central Intelligence Agency agent and the other a billionaire technology genius—work together using the ubiquitous surveillance system in New York City to try to stop violent crime. It’s referred to by some as a science fiction cop show. But the use of advanced technology for crime analysis in almost every major police department in the United States may surpass what’s depicted on TV crime dramas such as Person of Interest. Real-time crime cen- ters (RTCCs) are a vital aspect of intelligent policing. Crime analysis is no longer the stuff of science fiction. It’s real.
标签： Intelligence Analysis Crime
上传时间： 2020-05-25
上传用户：shancjb
YoumayaskwhyIwrotethisbook.Therearemany,manypersonalreasonsaswithanyauthor I suppose. The first two reasons and probably the most important are my love of flying and my love of radio engineering. This may sound rather dull but I love flying in any machine be it balloon, glider, propeller aircraft, microlight through to airline jets and the experience of it. The more I do it the more I feel I understand it.
标签： Communication Aeronautical Systems Radio
上传时间： 2020-05-26
上传用户：shancjb
Cooperation is not a natural characteristic attributed to humans. The typical human horizon is focused on short-term gains, which might be due to our instinct-driven subconscious occupying a grander importance than we dare to admit [1]. Cooperating with other individuals or entities, however, usually means that short-term losses may translate into long-term gains – something history has proved to hold true but humans for some reason rarely ever understand.
标签： Communications Cooperative
上传时间： 2020-05-27
上传用户：shancjb
Cellular communications is one of the fastest growing and most challenging telecom- munication applications ever. Today, it represents a large and continuously increasing percentage of all new telephone subscribers around the world. In the long term, cellular digital technology may become the universal way of communication.
标签： Engineering System GSM
上传时间： 2020-05-27
上传用户：shancjb
With the rapid expansion of wireless consumer products,there has been a con- siderable increase in the need for radio-frequency (RF) planning, link plan- ning, and propagation modeling.A network designer with no RF background may find himself/herself designing a wireless network. A wide array of RF planning software packages can provide some support, but there is no substi- tute for a fundamental understanding of the propagation process and the lim- itations of the models employed. Blind use of computer-aided design (CAD) programs with no understanding of the physical fundamentals underlying the process can be a recipe for disaster. Having witnessed the results of this approach, I hope to spare others this frustration.
标签： Introduction Propagation to RF
上传时间： 2020-05-27
上传用户：shancjb
Due to the asymmetry between the amount of data traffic in the downlink and uplink direction of nowadays and future wireless networks, a proper design of the transceivers in the broadcast channel is inevitable in order to satisfy the users’ demands on data rate and transmission quality. This book deals with the optimi- zation-based joint design of the transmit and receive filters in a MIMO broadcast channel in which the user terminals may be equipped with several antenna ele- ments.
上传时间： 2020-05-28
上传用户：shancjb
By definition, the term “mobile-radio communications” describes any radio communication link between two terminals of which one or both are in motion or halted at unspecified locations and of which one may actually be a fixed terminal such as a base station. This definition applies to both mobile-to-mobile and mobile-to-fixed radio communica- tion links. The mobile-to-mobile link could in fact consist of a mobile- to-fixed-to-mobile radio communication link.The term “mobile” applies to land vehicles, ships at sea, aircraft, and communications satellites. In tactical situations, mobile-radio systems may include any or all of these types of mobile terminals.
标签： Communications Engineering Mobile
上传时间： 2020-05-30
上传用户：shancjb
Advances in communication and networking technologies are rapidly making ubiq- uitous network connectivity a reality. Wireless networks are indispensable for supporting such access anywhere and at any time. Among various types of wire- less networks, multihop wireless networks (MWNs) have been attracting increasing attention for decades due to its broad civilian and military applications. Basically, a MWN is a network of nodes connected by wireless communication links. Due to the limited transmission range of the radio, many pairs of nodes in MWNs may not be able to communicate directly, hence they need other intermediate nodes to forward packets for them. Routing in such networks is an important issue and it poses great challenges.
标签： Multihop Wireless Networks
上传时间： 2020-05-31
上传用户：shancjb
