Wireless Mesh Networks (WMN) are believed to be a highly promising technology and will play an increasingly important role in future generation wireless mobile networks. WMN is characterized by dynamic self-organization, self-configuration and self-healing to enable quick deployment, easy maintenance, low cost, high scalability and reliable services, as well as enhancing network capacity, connect- ivity and resilience.
标签： Networking Wireless Mesh
上传时间： 2020-06-01
上传用户：shancjb
The explosion in demand for wireless services experienced over the past 20 years has put significant pressure on system designers to increase the capacity of the systems being deployed. While the spectral resource is very scarce and practically exhausted, the biggest possibilities are predicted to be in the areas of spectral reuse by unlicensed users or in exploiting the spatial dimension of the wireless channels. The former approach is now under intense development and is known as the cogni- tive radio approach (Haykin 2005).
标签： Multi-Antenna Wireless Channels Modeling
上传时间： 2020-06-01
上传用户：shancjb
The PW4556 series of devices are highly integrated Li-Ion and Li-Pol linear chargers targetedat small capacity battery for portable applications. It is a complete constant-current/ constantvoltage linear charger. No external sense resistor is needed, and no blocking diode is required dueto the internal MOSFET architecture. It can deliver up to 300mA of charge current (using a goodthermal PCB layout) with a final float voltage accuracy of ±1%. The charge voltage is fixed at 4.2V or4.35V, and the charge current can be programmed externally with a single resistor. The chargerfunction has high accuracy current and voltage regulation loops and charge termination
标签： pw4556
上传时间： 2022-02-11
上传用户：1208020161
以AT89S52单片机为控制核心,采用电容降压技术,Buck电路拓扑,PWM驱动模块和功率器件散热设计,通过高速的数据采集、主功率输入输出模块和控制模块,设计一种新型智能车载充电器.在充电过程中,通过负脉冲瞬间放电实现对铅酸蓄电池的再生修复,提高电池的有效容量,延长使用寿命.该充电器体积小、速度快、效率高、可靠性好.With AT89S52 single chip computer as the control core,a new type of intelligent car-carried charger was designed by using capacitance step-down technology,Buck circuit topology,PWM driving module and power device heat dissipation design,through high-speed data acquisition,main power input and output module and control module.In the charging process,the regeneration and repair of lead-acid batteries are realized by instantaneous discharge of negative pulse,which improves the effective capacity of batteries and prolongs their service life.The charger has the advantages of small size,fast speed,high efficiency and good reliability.
标签： 车载充电器
上传时间： 2022-03-27
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为设计高效率、低损耗的PFC电路,本文基于UCC28019进行电路设计。以UCC28019输出的PWM波形来控制Boost升压斩波为核心电路,使电路中的电容交替地充放电、电感交替的储存和释放能量,最后实现在输入AC20V~24V电压情况下稳定输出DC38V。测试结果表明,系统实现效率为95%左右,电压调整率小于1%,电源功率因数0.99。交流输入电压为19.0-25.8 V时,输出直流电压稳定性较好,电感无明显啸叫且纹波小,具有一定的带负载能力和实用性。In order to design the PFC circuit with high efficiency and low loss,this paper designs the circuit based on UCC28019.The PWM waveform output by UCC28019 is used to control boost chopper as the core circuit,which alternately charges and discharges capacitors,stores and releases energy by inductors,and finally achieves stable output of DC38 V under the input voltage of AC20 V~24 V.The test results show that the system achieves about 95% efficiency,the voltage adjustment rate is less than 1%,the power factor is 0.99,and the AC input voltage is 19.0-25.8 V.The output DC voltage stability is good,the inductance has no obvious whistle and the ripple is small,so it has certain load capacity and practicability.
上传时间： 2022-04-03
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The following table covers the main features offered by the MT7628KN and MT7628AN. Overall, the MT7628KN supports the requirements of an entry level AP/router, while the more advanced MT7628AN supports a number of interfaces together with a large maximum RAM capacity.Features· Embedded MIPS24KEc (575/580 MHz) with 64KBl-Cache and 32KB D-Cache·2T2R 2.4GHz with 300 Mbps PHY data rate· Legacy 802.11b/g and HT 802.11n modes·20/40 MHz channel bandwidth· Reverse Data Grant(RDG)· Maximal Ratio Combining(MRC)· Space Time Block Coding(STBC)· MCM 8 Mbytes DDR1 KGD(MT7628KN)·16-bit DDR1/2 up to 128/256 Mbytes(MT7628AN/KN)· SPI/SD-XC/eMMC·x1 USB 2.0 Host,x1 Ple Root Complex·5-port 10/100 FE PHY
标签： mt7628
上传时间： 2022-07-25
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