關于太赫茲微波窗的設計,寬帶傳輸,220GHz頻率左右。
標簽: 微波窗
上傳時間: 2016-01-04
上傳用戶:winner79
In this paper, we consider the channel estimation problem in Millimeter wave (mmWave) wireless systems with large antenna arrays. By exploiting the inherent sparse nature of the mmWave channel, we develop a novel rate-adaptive channel estimation (RACE) algorithm, which can adaptively adjust the number of required channel measurements based on an expected probability of estimation error (PEE).
標簽: Estimation Millimeter Adaptive Approach Channel Systems Rate MIMO Wave for
上傳時間: 2020-05-26
上傳用戶:shancjb
The telecommunications industry is undoubtedly in a period of radical change with the advent of mobile broadband radio access and the rapid convergence of Internet and mobile services. Some of these changes have been enabled by a fundamental shift in the underlying technologies; mobile networks are now increasingly based on a pure Internet Protocol (IP) network architecture. Since the first edition of this book was published in 2009, a multitude of connected devices from eBook readers to smartphones and even Machine-to-Machine (M2M) technologies have all started to benefit from mobile broadband. The sea change over the last few years is only the beginning of a wave of new services that will fundamentally change our economy, our society, and even our environment. The evolution towards mobile broadband is one of the core underlying parts of this revolution and is the focus of this book.
標簽: Networks Packet EPC and 4G
上傳時間: 2020-05-27
上傳用戶:shancjb
The objective of this book is to allow the reader to predict the received signal power produced by a particular radio transmitter. The first two chapters examine propagation in free space for point-to-point and point-to-area transmission, respectively. This is combined with a dis- cussion regarding the characteristics of antennas for various purposes. In chapter 3, the effect of obstacles, whether buildings or mountains, is discussed and analytical methods, whereby the strength of a signal is the shadow of an obstacle can be predicted, are presented.
標簽: Propagation Essentials Radio Wave of
上傳時間: 2020-05-27
上傳用戶:shancjb
In the nineteenth century, scientists, mathematician, engineers and innovators started investigating electromagnetism. The theory that underpins wireless communications was formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi demonstrated the first wireless transmission. Since then, the range of applications has expanded at an immense rate, together with the underpinning technology. The rate of development has been incredible and today the level of technical and commercial maturity is very high. This success would not have been possible without understanding radio- wave propagation. This knowledge enables us to design successful systems and networks, together with waveforms, antennal and transceiver architectures. The radio channel is the cornerstone to the operation of any wireless system.
標簽: LTE-Advanced Generation Next and
上傳時間: 2020-05-27
上傳用戶:shancjb
One of the prerequisites for the development of telecommunication services is the understanding of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio waves: this term apply to the electromagnetic waves used in radio communications. Their frequency spectrum is very broad, and is divided into the following frequency bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves (300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub- EHF waves (300-3000 GHz).
標簽: Propagation Radio Wave
上傳時間: 2020-06-01
上傳用戶:shancjb
The focus of this book is on developing computational algorithms for transmit wave- form design in active sensing applications, such as radar, sonar, communications and medical imaging. Waveforms are designed to achieve certain desired properties, which are divided into three categories corresponding to the three main parts in the book, namely good aperiodic correlations, good periodic correlations and beampattern match- ing.
上傳時間: 2020-06-01
上傳用戶:shancjb
Over many years, RF-MEMS have been a hot topic in research at the technology and device level. In particular, various kinds of mechanical Si-MEMS resonators and piezoelectric BAW (bulk acoustic wave) resonators have been developed. The BAW technology has made its way to commercial products for passive RF filters, in particular for duplexers in RF transceiver front ends for cellular communica- tions. Beyond their use in filters, micromachined resonators can also be used in conjunction with active devices in innovative circuits and architectures.
標簽: MEMS-based Circuits Systems and
上傳時間: 2020-06-06
上傳用戶:shancjb
In the first chapter, the topic of this book is classified into the area of pervasive com- puting. Further, security and privacy in the scope of RFID technology is motivated and the vision that guides the remainder of this book is introduced.
標簽: RFID_Security_and_Privacy_Concept
上傳時間: 2020-06-08
上傳用戶:shancjb
With more than two billion terminals in commercial operation world-wide, wire- less and mobile technologies have enabled a first wave of pervasive communication systems and applications. Still, this is only the beginning as wireless technologies such as RFID are currently contemplated with a deployment potential of tens of billions of tags and a virtually unlimited application potential. A recent ITU report depicts a scenario of “Internet of things” — a world in which billions of objects will report their location, identity, and history over wireless connections.
標簽: Internet Things From The RFI of
上傳時間: 2020-06-08
上傳用戶:shancjb