直流支撐電容器，又稱DC-Link電容器。直流支撐電容器，屬于無源器件的一種。直流支撐電容器，現(xiàn)主要采用聚丙烯薄膜介質(zhì)直流支撐電容器，其具有耐電壓高、耐電流大、低阻抗、低電感、容量損耗小、漏電流小、溫度性能好、充放電速度快、使用壽命長(約10萬小時(shí))、安全防爆穩(wěn)定性好、無極性安裝方便等優(yōu)點(diǎn)。被廣泛應(yīng)用于電力電子行業(yè)
上傳時(shí)間： 2019-06-16
上傳用戶：abcdyifei
pcie3.0標(biāo)準(zhǔn)規(guī)范 1. INTRODUCTION 2. TRANSACTION LAYER SPECIFICATION 3. DATA LINK LAYER SPECIFICATION 4. PHYSICAL LAYER SPECIFICATION 5. POWER MANAGEMENT 6. SYSTEM ARCHITECTURE 7. SOFTWARE INITIALIZATION AND CONFIGURATION
標(biāo)簽： pcie3
上傳時(shí)間： 2019-07-05
上傳用戶：bingshi
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.
標(biāo)簽： Technology Cellular Radio 3GPP LTE and
上傳時(shí)間： 2020-05-26
上傳用戶：shancjb
One traditional view of how wireless networks evolve is of a continuous, inevitable progres- sion to higher link speeds, combined with greater mobility over wider areas. This standpoint certainly captures the development from first and second generation cellular systems focused on voice support, and the early short-range wireless data networks, through to today’s 3G cellular and mobile broadband systems; there is every confidence that the trend will continue some way into the future.
上傳時(shí)間： 2020-05-26
上傳用戶：shancjb
Multiuser multiple-input-multiple-output (MU- MIMO) systems are known to be hindered by dimensionality loss due to channel state information (CSI) acquisition overhead. In this paper, we investigate user-scheduling in MU-MIMO systems on account of CSI acquisition overhead, where a base station dynamically acquires user channels to avoid choking the system with CSI overhead.
標(biāo)簽： Acquisition Dynamic Channel
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
The next-generation wireless broadband technology is changing the way we work, live, learn, and communicate through effective use of state- of-the-art mobile broadband technology. The packet-data-based revolu- tion started around 2000 with the introduction of 1x Evolved Data Only (1xEV-DO) and 1x Evolved Data Voice (1xEV-DV) in 3GPP2 and High Speed Downlink Packet Access (HSDPA) in 3GPP. The wireless broad- band fourth-generation technology (4G) is an evolution of the packet- based 3G system and provides a comprehensive evolution of the Universal Mobile Telecommunications System specifications so as to remain competitive with other broadband systems such as 802.16e (WiMAX)
標(biāo)簽： Essentials LTE-A LTE and of
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
During the past decade, many wireless communication techniques have been developedto achievevariousgoals suchas higherdata rate,morerobustlink quality, and higher number of users in a given bandwidth. For wireless communication systems, depending on the availability of a feedback link, two approaches can be considered: namely open and closed loop. Open loop communication system that does not exploit the channel knowledge at the transmitter is now well understood from both a theoretical and practical point of view.
標(biāo)簽： Communication Strategies Feedback Wireless for
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
This book was conceived in such a special way. From our experience, and despite the increasing interest that we perceived amongst the research community in HAPS, there was not any book in the market entirely devoted to HAPS. We could only find some satellite communications books including only fragments related to HAPS, covering the ‘generalities’. A need for a reference book which could highlight state- of-the-art HAPS-related topics was therefore envisaged. Moreover, most of the information related to HAPS could only be found in technical reports, official recommendations, conference proceedings and journal papers.
標(biāo)簽： High-Altitude Platforms
上傳時(shí)間： 2020-05-27
上傳用戶：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.
標(biāo)簽： Introduction Propagation to RF
上傳時(shí)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(biāo)簽： Large-scale Antenna Systems
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
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