When the authors of this book asked me to write the foreword of their work on the digital enterprise, I immediately thought that it was one more document on a fashionable topic in the technology and the business world of the 21st Century often addressed by consulting firms, some of which have aspired to become experts on the subject. However, a more careful observation reveals that an issue more important than the sole subject of the digital enterprise is: “Is your company fully operational?”, because this is the real topic.
標簽: Digital_Transformation_Informatio n_System
上傳時間: 2020-05-27
上傳用戶:shancjb
The recent developments in full duplex (FD) commu- nication promise doubling the capacity of cellular networks using self interference cancellation (SIC) techniques. FD small cells with device-to-device (D2D) communication links could achieve the expected capacity of the future cellular networks (5G). In this work, we consider joint scheduling and dynamic power algorithm (DPA) for a single cell FD small cell network with D2D links (D2DLs). We formulate the optimal user selection and power control as a non-linear programming (NLP) optimization problem to get the optimal user scheduling and transmission power in a given TTI. Our numerical results show that using DPA gives better overall throughput performance than full power transmission algorithm (FPA). Also, simultaneous transmissions (combination of uplink (UL), downlink (DL), and D2D occur 80% of the time thereby increasing the spectral efficiency and network capacity
標簽: Full-Duplex Cells Small
上傳時間: 2020-05-27
上傳用戶:shancjb
The wireless market has experienced a phenomenal growth since the first second- generation (2G) digital cellular networks, based on global system for mobile communications (GSM) technology, were introduced in the early 1990s. Since then, GSM has become the dominant global 2G radio access standard. Almost 80% of today’s new subscriptions take place in one of the more than 460 cellular networks that use GSM technology. This growth has taken place simultaneously with the large experienced expansion of access to the Internet and its related multimedia services.
標簽: Performance Evolution GPRS EDGE GSM and
上傳時間: 2020-05-27
上傳用戶:shancjb
In this paper we revisit hybrid analog-digital precoding systems with emphasis on their modelling and radio-frequency (RF) losses, to realistically evaluate their benefits in 5G system implementations. For this, we decompose the analog beamforming networks (ABFN) as a bank of commonly used RF components and formulate realistic model constraints based on their S-parameters. Specifically, we concentrate on fully-connected ABFN (FC-ABFN) and Butler networks for implementing the discrete Fourier transform (DFT) in the RF domain. The results presented in this paper reveal that the performance and energy efficiency of hybrid precoding systems are severely affected, once practical factors are considered in the overall design. In this context, we also show that Butler RF networks are capable of providing better performances than FC-ABFN for systems with a large number of RF chains.
標簽: Analog-Digital Precoding Hybrid
上傳時間: 2020-05-27
上傳用戶:shancjb
Communication, a word that many associate with modern technology, actually has nothing to do with technology. At its core, communication involves nothing more than the spoken or written word, and symbolic languages like art and music. Technology has become synonymous with communication because technology has historically been the method by which communication to or by the general population takes place.
標簽: Implementing 802.11
上傳時間: 2020-05-27
上傳用戶:shancjb
When digital media is perceived only as a tool to deliver content the potential for using its affordances to explore meaning is lost. Rather than seeing media only as an access point, we can view it as a way to enhance the expressiveness of content. Today blogs, wikis, messaging, mash-ups, and social media (Facebook, Twitter, YouTube and others) offer authors ways to create narrative meaning that refl ects our new media culture. We can look to the past for similarities and parallels to better understand how to use social media as a creative tool with which to dialogue, collaborate, and create interactive narratives.
標簽: Interactivity Social Media in
上傳時間: 2020-05-27
上傳用戶:shancjb
The third generation (3G) mobile communication system is the next big thing in the world of mobile telecommunications. The first generation included analog mobile phones [e.g., Total Access Communications Systems (TACS), Nordic Mobile Telephone (NMT), and Advanced Mobile Phone Service (AMPS)], and the second generation (2G) included digital mobile phones [e.g., global system for mobile communications (GSM), personal digital cellular (PDC), and digital AMPS (D-AMPS)]. The 3G will bring digital multimedia handsets with high data transmission rates, capable of providing much more than basic voice calls.
標簽: Communications Introduction Mobile 3G to
上傳時間: 2020-05-27
上傳用戶:shancjb
To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation (5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation (4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI) acquisition, wireless transmission technology, and resource allocation.
標簽: Large-scale Antenna Systems
上傳時間: 2020-05-27
上傳用戶:shancjb
When we started thinking about writing the first edition of this book a few years ago, we had been working together for more than five years on the borderline between propagation and signal processing. Therefore, it is not surprising that this book deals with propagation models and design tools for MIMO wireless communications. Yet, this book should constitute more than a simple combination of these two domains. It hopefully conveys our integrated understanding of MIMO, which results from endless controversial discussions on various multi-antenna related issues, as well as various interactions with numerous colleagues. Obviously, this area of technology is so large that it is beyond our aim to cover all aspects in details. Rather, our goal is to provide researchers, R&D engineers and graduate students with a comprehensive coverage of radio propagation models and space–time signal processing techniques for multi-antenna, multi-user and multi-cell networks.
上傳時間: 2020-05-28
上傳用戶:shancjb
Use of multiple antennas at both ends of wireless links is the result of the natural progression of more than four decades of evolution of adaptive antenna technology. Recent advances have demonstrated that multiple- input-multiple-output (MIMO) wireless systems can achieve impressive increases in overall system performance.
標簽: Technology System MIMO
上傳時間: 2020-05-28
上傳用戶:shancjb