Level Crossing Rate in Terms of the Characteristic Function: A New Approach for Calculating the Fading Rate in diversity Systems
标签： Characteristic Calculating the Crossing
上传时间： 2016-02-19
上传用户：shinesyh
Frequency domain characterization of los nonfading indoor wireless LAN channel employing frequency and polarization diversity in the 63.4 to 65.4GHz band
标签： characterization Frequency employing frequency
上传时间： 2013-12-22
上传用户：zhaoq123
ieee754的标准，原英文版的！Twenty years ago anarchy threatened floating-point arithmetic. Over a dozen commercially significant arithmetics boasted diverse wordsizes, precisions, rounding procedures and over/underflow behaviors, and more were in the works. “Portable” software intended to reconcile that numerical diversity had become unbearably costly to develop. Thirteen years ago, when IEEE 754 became official, major microprocessor manufacturers had already adopted it despite the challenge it posed to implementors. With unprecedented altruism, hardware designers had risen to its challenge in the belief that they would ease and encourage a vast burgeoning of numerical software. They did succeed to a considerable extent. Anyway, rounding anomalies that preoccupied all of us in the 1970s afflict only CRAY X-MPs — J90s now.
上传时间： 2017-07-28
上传用户：894898248
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
Smart City Networks: Through the Internet of Things is composed of research results, analyses, and ideas, which focus on a diversity of interconnected factors relating with urbanization, its “smartness,” and overarching “internet of things (IoT).” The latter refers to interconnected objects and devices – through compu- tational operations – which can receive signals and actuate systems.
标签： Networks Internet Through Things Smart City
上传时间： 2020-05-26
上传用户：shancjb
Relaying techniques, in which a source node communicates to a destination node with the help of a relay, have been proposed as a cost-effective solution to address the increasing demand for high data rates and reliable services over the air. As such, it is crucial to design relay systems that are able to not only provide high spectral efficiency, but also fully exploit the diversity of the relay channel.
标签： Amplify-and-Forward Relaying
上传时间： 2020-05-26
上传用户：shancjb
Employing multiple transmit and receive antennas, namely using multi-input multi-output (MIMO) systems, has proven to be a major breakthrough in providing reliable wireless communication links. Since their invention in the mid-1990s, transmit diversity, achieved through space-time coding, and spatial multiplexing schemes have been the focus of much research in the area of wireless communications.
标签： Communication Systems Coding MIMO for
上传时间： 2020-05-26
上传用户：shancjb
Optical communication technology has been extensively developed over the last 50 years, since the proposed idea by Kao and Hockham [1]. However, only during the last 15 years have the concepts of communication foundation, that is, the modulation and demodulation techniques, been applied. This is pos- sible due to processing signals using real and imaginary components in the baseband in the digital domain. The baseband signals can be recovered from the optical passband region using polarization and phase diversity tech- niques, as well as technology that was developed in the mid-1980s.
标签： Transmission Processing Digital Optical
上传时间： 2020-05-27
上传用户：shancjb
In this book, we study the interference cancellation and detection problem in multiantenna multi-user scenario using precoders. The goal is to utilize multiple antennas to cancel the interference without sacrificing the diversity or the com- plexity of the system.
标签： Cancellation6 Interference
上传时间： 2020-05-27
上传用户：shancjb
Multi-carrier modulation‚ Orthogonal Frequency Division Multi- plexing (OFDM) particularly‚ has been successfully applied to a wide variety of digital communications applications over the past several years. Although OFDM has been chosen as the physical layer standard for a diversity of important systems‚ the theory‚ algorithms‚ and implementation techniques remain subjects of current interest. This is clear from the high volume of papers appearing in technical journals and conferences.
标签： COMMUNICATIONS MULTI-CARRIER DIGITAL
上传时间： 2020-05-31
上传用户：shancjb
