Wireless communications has become a field of enormous scientific and economic interest. Recent success stories include 2G and 3G cellular voice and data services (e.g., GSM and UMTS), wireless local area networks (WiFi/IEEE 802.11x), wireless broadband access (WiMAX/IEEE 802.16x), and digital broadcast systems (DVB, DAB, DRM). On the physical layer side, traditional designs typically assume that the radio channel remains constant for the duration of a data block. However, researchers and system designers are increasingly shifting their attention to channels that may vary within a block. In addition to time dispersion caused by multipath propagation, these rapidly time-varying channels feature frequency dispersion resulting from the Doppler effect. They are, thus, often referred to as being “doubly dispersive.”
标签： Time-Varying Channels
上传时间： 2020-06-01
上传用户：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.
标签： Maximization Nonconvex Wireless Utility Systems in
上传时间： 2020-06-01
上传用户：shancjb
Plug in Electric Vehicles (PEVs) use energy storages usually in the form of battery banks that are designed to be recharged using utility grid power. One category of PEVs are Electric Vehicles (EVs) without an internal-combustion (IC) engine where the energy stored in the battery bank is the only source of power to drive the vehicle. These are also referred as Battery Electric Vehicles (BEVs). The second category of PEVs, which is more commercialized than the EVs, is the Plug in
标签： Electric Vehicles Grids Smart Plug In in
上传时间： 2020-06-07
上传用户：shancjb
Plug in Electric Vehicles (PEVs) use energy storages usually in the form of battery banks that are designed to be recharged using utility grid power. One category of PEVs are Electric Vehicles (EVs) without an Internal-Combustion (IC) engine where the energy stored in the battery bank is the only source of power to drive the vehicle. These are also referred as Battery Electric Vehicles (BEVs). The second category of PEVs, which is more commercialized than the EVs, is Plug in Hybrid Electric Vehicles (PHEVs) where the role of the energy storage is to supplement the power produced by the IC engine.
上传时间： 2020-06-07
上传用户：shancjb
Plug in Electric Vehicles (PEVs) use energy storages usually in the form of battery banks that are designed to be recharged using utility grid power. One category of PEVs are Electric Vehicles (EVs) without an Internal-Combustion (IC) engine where the energy stored in the battery bank is the only source of power to drive the vehicle. These are also referred to as Battery Electric Vehicles (BEVs). The second category of PEVs, which is more commercialized than the EVs, is the Plug in Hybrid Electric Vehicles (PHEVs) where the role of energy storage is to supplement the power produced by the IC engine.
标签： Electric Vehicles Smart Grids in
上传时间： 2020-06-07
上传用户：shancjb
stract With global drivers such as better energy consumption, energy efficiency and reduction of greenhouse gases, CO 2 emission reduction has become key in every layer of the value chain. Power Electronics has definitely a role to play in these thrilling challenges. From converters down to compound semiconductors, innovation is leading to breakthrough technologies. Wide BandGap, Power Module Packaging, growth of Electric Vehicle market will game change the overall power electronic industry and supply chain. In this presentation we will review power electronics trends, from technologies to markets.
标签： Electronics Materials Power WBG for
上传时间： 2020-06-07
上传用户：shancjb
Recent work has shown that convolutional networks can be substantially deeper, more accurate, and efficient to train if they contain shorter connections between layers close to the input and those close to the output. In this paper, we embrace this observation and introduce the Dense Convo- lutional Network (DenseNet), which connects each layer to every other layer in a feed-forward fashion.
标签： Convolutional Connected Networks Densely
上传时间： 2020-06-10
上传用户：shancjb
如果 PCB 用排线连接，控制排线对应的插头插座必须成直线，不交叉、不扭曲。 连续的 40PIN 排针、排插必须隔开 2mm 以上。 考虑信号流向，合理安排布局，使信号流向尽可能保持一致。 输入、输出元件尽量远离。 电压的元器件应尽量放在调试时手不易触及的地方。 驱动芯片应靠近连接器。 有高频连线的元件尽可能靠近，以减少高频信号的分布参数和电磁干扰。 对于同一功能或模组电路，分立元件靠近芯片放置。 连接器根据实际情况必须尽量靠边放置。 开关电源尽量靠近输入电源座。 BGA 等封装的元器件不应放于 PCB 板正中间等易变形区 BGA 等阵列器件不能放在底面， PLCC 、 QFP 等器件不宜放在底层。 多个电感近距离放置时应相互垂直以消除互感。 元件的放置尽量做到模块化并连线最短。 在保证电气性能的前提下，尽量按照均匀分布、重心平衡、版面美观的标准优化布局。 按电路模块进行布局，实现同一功能的相关电路称为一个模块，电路模块中的元件应采用就近集 中原则，同时数字电路和模拟电路分开； 定位孔、标准孔等非安装孔周围 1.27mm 内不得贴装元、器件，螺钉等安装孔周围 紧固件安装孔、椭圆孔及板中其它方孔外侧距板边的尺寸大于 3mm ； 发热元件不能紧邻导线和热敏元件；高热器件要均衡分布；
上传时间： 2021-06-25
上传用户：xiangshuai
核心板说明（1）DDR模板：RK3288-LPDDR3P232SD6-V12-20140623HXS（2）适用的平台：RK3288；（3）支持的DDR类型：LPDDR3_2PCS*32BIT（4）最大支持容量：4G（2PCS*32BIT）；（5）板层：6 Layer；（6）贴片方式：DDR器件单面贴,其它器件双面贴；（7）面积：35mm*35mm；
上传时间： 2022-02-02
上传用户：
ST提供适用于SLC的NFTL（NAND Flash Translation Layer）和FAT类文件系统来解决NAND Flash存储的问题。
标签： flash
上传时间： 2022-02-21
上传用户：trh505
