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.
标签： Acquisition Dynamic Channel
上传时间： 2020-05-27
上传用户：shancjb
This book addresses two aspects of network operation quality; namely, resource management and fault management. Network operation quality is among the functions to be fulfilled in order to offer quality of service, QoS, to the end user. It is characterized by four parameters: – packet loss; – delay; – jitter, or the variation of delay over time; – availability. Resource management employs mechanisms that enable the first three parameters to be guaranteed or optimized. Fault management aims to ensure continuity of service.
标签： Ethernet Networks MPLS and IP
上传时间： 2020-05-27
上传用户：shancjb
At the macroscopic level of system layout, the most important issue is path loss. In the older mobile radio systems that are limited by receiver noise, path loss determines SNR and the maximum coverage area. In cellular systems, where the limiting factor is cochannel interference, path loss determines the degree to which transmitters in different cells interfere with each other, and therefore the minimum separation before channels can be reused.
标签： Characteristics Channel Mobile
上传时间： 2020-05-30
上传用户：shancjb
his research aims at creating broadband tunable, fully integrated filters for the application of cognitive radio and signal classification receivers. The approach under study is the N-path filter technique which is capable of translating a baseband impedance to a reference frequency creating a tunable filter. The traditional N-path filter suffers from fundamental architectural limitations, namely : a trade-off between insertion loss and out-of-band rejection, reference clock feed- through, and jammer power handling limitations. In the first approach, the fundamental trade- off of the traditional N-path filter between insertion loss and out-of-band rejection is improved by a transmission line (T-line) N-path filter technique.
上传时间： 2020-05-31
上传用户：shancjb
Power Electronics is one of modern and key technologies in Electrical and Electronics Engineering for green power, sustainable energy systems, and smart grids. Especially, the transformation of existing electric power systems into smart grids is currently a global trend. The gradual increase of distributed generators in smart grids indicates a wide and important role for power electronic converters in the electric power system, also with the increased use of power electronics devices (nonlinear loads) and motor loadings, low cost, low-loss and high-performance shunt current quality compensators are highly demanded by power customers to solve current quality problems caused by those loadings.
标签： Electronics Parallel Filters Power
上传时间： 2020-06-07
上传用户：shancjb
Radio frequency identifi cation (RFID) technology is a wireless communication technology that enables users to uniquely identify tagged objects or people. RFID is rapidly becoming a cost-effective technology. This is in large part due to the efforts of Wal-Mart and the Department of Defense (DoD) to incorporate RFID technology into their supply chains. In 2003, with the aim of enabling pallet-level tracking of inventory, Wal-Mart issued an RFID mandate requiring its top suppliers to begin tagging pallets and cases, with Electronic Product Code (EPC) labels. The DoD quickly followed suit and issued the same mandate to its top 100 suppliers. This drive to incorporate RFID technology into their supply chains is motivated by the increased ship- ping, receiving and stocking effi ciency and the decreased costs of labor, storage, and product loss that pallet-level visibility of inventory can offer.
标签： A_Guide_to_Radio_Frequency_IDenti fication RFID
上传时间： 2020-06-08
上传用户：shancjb
STM32L053C8T6数据手册Features • Ultra-low-power platform – 1.65 V to 3.6 V power supply – -40 to 125 °C temperature range – 0.27 µA Standby mode (2 wakeup pins) – 0.4 µA Stop mode (16 wakeup lines) – 0.8 µA Stop mode + RTC + 8 KB RAM retention – 139 µA/MHz Run mode at 32 MHz – 3.5 µs wakeup time (from RAM) – 5 µs wakeup time (from Flash) • Core: ARM® 32-bit Cortex®-M0+ with MPU – From 32 kHz up to 32 MHz max. – 0.95 DMIPS/MHz • Reset and supply management – Ultra-safe, low-power BOR (brownout reset) with 5 selectable thresholds – Ultralow power POR/PDR – Programmable voltage detector (PVD) • Clock sources – 1 to 25 MHz crystal oscillator – 32 kHz oscillator for RTC with calibration – High speed internal 16 MHz factory-trimmed RC (+/- 1%) – Internal low-power 37 kHz RC – Internal multispeed low-power 65 kHz to 4.2 MHz RC – PLL for CPU clock • Pre-programmed bootloader – USART, SPI supported • Development support – Serial wire debug supported • Up to 51 fast I/Os (45 I/Os 5V tolerant) • Memories – Up to 64 KB Flash with ECC – 8KB RAM – 2 KB of data EEPROM with ECC – 20-byte backup register
标签： stm32l053c8t6
上传时间： 2022-02-06
上传用户：
PW2330 develops a high efficiency synchronous step down DC-DC converter capable of delivering3A output current. PW2330 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss. PW2330 adopts the proprietary instant PWM architecture to achieve fast transient responsesfor high step down applications and high efficiency at light loads. In addition, it operates atpseudo-constant frequency of 500kHz under continuous conduction mode to minimize the size ofinductor and capacitor
标签： pw2330
上传时间： 2022-02-11
上传用户：
PW2205 develops a high efficiency synchronous step-down DC-DC converter capable of delivering5A output current. PW2205 operates over a wide input voltage range from 4.5V to 30V andintegrates main switch and synchronous switch with very low RDS(ON) to minimize the conductionloss.PW2205 adopts the instant PWM architecture to achieve fast transient responses for high step downapplications and high efficiency at light loads. In addition, it operates at pseudo-constant frequencyof 500kHz under continuous conduction mode to minimize the size of inductor and capacitor
标签： pw2205
上传时间： 2022-02-11
上传用户：
The PW2202 is silicon N-channel Enhanced VDMOSFETs, is obtained by the self-aligned planarTechnology which reduce the conduction loss, improve switching performance and enhance theavalanche energy. The transistor can be used in various power switching circuit for system
标签： pw2202
上传时间： 2022-02-11
上传用户：默默
