A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own wireless link. The signal received from the link transmitter may be jammed by the signals received from the other transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all transmitters, except its own transmitter.
標簽： Stochastic Geometry Networks Wireless Volume and II
上傳時間： 2020-06-01
上傳用戶：shancjb
Changes in telecommunications are impacting all types of user group, which include business users, traveling users, small and home offices, and residential users. The acceptance rate of telecom- munications and information services is accelerating significantly. Voice services needed approximately 50 years to reach a very high teledensity; television needed just 15 years to change the culture and lives of many families; the Internet and its related services have been penetrating and changing business practices and private com- munications over the last 2 to 3 years.
標簽： Telecommunications Handbook The
上傳時間： 2020-06-01
上傳用戶：shancjb
Once upon a time, cellular wireless networks provided two basic services: voice telephony and low-rate text messaging. Users in the network were separated by orthogonal multiple access schemes, and cells by generous frequency reuse patterns [1]. Since then, the proliferation of wireless services, fierce competition, andthe emergenceof new service classes such as wireless data and multimediahave resulted in an ever increasing pressure on network operators to use resources in a moreefficient manner.In the contextof wireless networks,two of the most common resources are power and spectrum—and, due to regulations, these resources are typically scarce. Hence, in contrast to wired networks, overprovisioning is not feasible in wireless networks.
標簽： Maximization Nonconvex Wireless Utility Systems in
上傳時間： 2020-06-01
上傳用戶：shancjb
Second-generation telecommunication systems, such as the Global System for Mobile Communications (GSM), enabled voice traffic to go wireless: the number of mobile phones exceeds the number of landline phones and the mobile phone penetration is approaching 100% in several markets. The data-handling capabilities of second-generation systems are limited, however, and third-generation systems are needed to provide the high bit-rate services that enable high-quality images and video to be transmitted and received, and to provide access to the Web with higher data rates.
標簽： Evolution WCDMA UMTS HSPA LTE for and
上傳時間： 2020-06-01
上傳用戶：shancjb
Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts.
標簽： Communications Algorithmic Techniques Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
Mobile radio communications are evolving from pure telephony systems to multimedia platforms offering a variety of services ranging from simple file transfers and audio and video streaming, to interactive applications and positioning tasks. Naturally, these services have different constraints concerning data rate, delay, and reliability (quality-of-service (QoS)). Hence, future mobile radio systems have to provide a large flexibility and scal- ability to match these heterogeneous requirements.
標簽： Communications Wireless Channels MIMO over
上傳時間： 2020-06-01
上傳用戶：shancjb
Thanks to the advances in micromachining fabrication technologies and significant cost reduction due to mass production, miniature sensors of angular rate, or gyroscopes, found their way into the everyday life of every user of modern gadgets, such as smart phones, tablets or even wristwatches. Often without realising, many of us are carrying in our pockets fully equipped with all necessary sensors complete inertial navigation systems that not so long ago were available only for advanced vehicles in sea, land, air or space. Accelerometers and gyroscopes are found in specifications of any gadget supposed to react to user movements. And one of the most commonly used type of gyroscopes used to developed these systems is Coriolis vibratory gyroscope (CVG).
標簽： Gyroscopes Vibratory Coriolis
上傳時間： 2020-06-06
上傳用戶：shancjb
基于界面操作的人臉心率檢測的代碼，通過攝像頭實時采集人視頻，并計算心率(Face the heart rate detection interface operation based on the code, through real-time acquisition one camera video, and rate)
上傳時間： 2021-02-24
上傳用戶：
HRVAS is a complete and self-contained heart rate variability analysis software (HRVAS) package. HRVAS offers several preprocessing options. HRVAS offers time-domeain, freq-domain, time-frequency, and nonlinear HRV analysis. All results can be exported to an Excel file. For processing many files HRVAS offers a bach processing feature. All settings/options can be saved to a .mat file and reloaded for future HRV analysis. Upon starting HRVAS all previously used settings/options are loaded.
標簽： HRVAS時頻分析
上傳時間： 2021-09-19
上傳用戶：boboo
The PC1099N from Pixelplus is a CMOS Image Sensor with Mega Pixels 0.3 MP, VGA, Supply Voltage Analog: 3.3 V, HVDD: 3.3 V, CVDD: 3.3 V, Frame rate 50 to 60 fps, Dynamic Range 63.2 dB, SNR 45.3 dB. More details for PC1099N can be seen below.
標簽： pc1099n
上傳時間： 2021-12-12
上傳用戶：qingfengchizhu
