解读 5G 八大关键技术 【摘要】5G 不是一次革命,5G 是 4G 的延续,我相信 5G 在核心网部分不会有太 大的变动,5G 的关键技术集中在无线部分。 在进入主题之前,我觉得首先应该弄清楚一个问题:为什么需要 5G?不是因 为通信工程师们突然想改变世界,而炮制了一个 5G。是因为先有了需求,才有了 5G。什么需求? 未来的网络将会面对:1000 倍的数据容量增长,10 到 100 倍的无线设备连接, 10 到 100 倍的用户速率需求,10 倍长的电池续航时间需求等等。坦白的讲,4G 网络无法满足这些需求,所以 5G 就必须登场。 但是,5G 不是一次革命。5G 是 4G 的延续,我相信 5G 在核心网部分不会有 太大的变动,5G 的关键技术集中在无线部分。虽然 5G 最终将采用何种技术,目前 还没有定论。不过,综合各大高端论坛讨论的焦点,我今天收集了 8 大关键技术。 当然,应该远不止这些。 1.非正交多址接入技术 (Non-Orthogonal Multiple Access,NOMA) 我们知道 3G 采用直接序列码分多址(Direct Sequence CDMA ,DS-CDMA) 技术,手机接收端使用 Rake 接收器,由于其非正交特性,就得使用快速功率控制 (Fast transmission power control ,TPC)来解决手机和小区之间的远-近问题。 而 4G 网络则采用正交频分多址(
标签: 5G
上传时间: 2022-02-25
上传用户:20125101110
ADC模数转换器件Altium Designer AD原理图库元件库SV text has been written to file : 4.4 - ADC模数转换器件.csvLibrary Component Count : 29Name Description----------------------------------------------------------------------------------------------------ADC0800 National 8-Bit Analog to Digital ConverterADC0809 ADC0831 ADCADC0832 ADC8 Generic 8-Bit A/D ConverterCLC532 High-Speed 2:1 Analog MultiplexerCS5511 National 16-Bit Analog to Digital ConverterDAC8 Generic 8-Bit D/A ConverterEL1501 Differential line Driver/ReceiverEL2082 Current-Mode MultiplierEL4083 Current Mode Four Quadrant MultiplierEL4089 DC Restored Video AmplifierEL4094 Video Gain Control/FaderEL4095 Video Gain Contol/Fader/MultiplexerICL7106 LMC6953_NSC PCI Local Bus Power SupervisorMAX4147 300MHz, Low-Power, High-Output-Current, Differential Line DriverMAX4158 350MHz 2-Channel Video Multiplexer-AmplifierMAX4159 350MHz 2-Channel Video Multiplexer-AmplifierMAX4258 250MHz, 2-Channel Video Multiplexer-AmplifierMAX4259 250MHz 2-Channel Video Multiplexer-AmplifierMAX951 Ultra-Low-Power, Single-Supply Op Amp + Comparator + ReferenceMAX952 Ultra-Low-Power, Single-Supply Op Amp + Comparator + ReferenceMC1496 Balanced Modulator/DemodulatorPLL100k Generic Phase Locked LoopPLL10k Generic Phase Locked LoopPLL5k Generic Phase Locked LoopPLLx Generic Phase Locked Loop水位计
标签: adc 模数转换 altium designer
上传时间: 2022-03-13
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电子书-RTL Design Style Guide for Verilog HDL540页A FF having a fixed input value is generated from the description in the upper portion of Example 2-21. In this case, ’0’ is output when the reset signal is asynchronously input, and ’1’ is output when the START signal rises. Therefore, the FF data input is fixed at the power supply, since the typical value ’1’ is output following the rise of the START signal. When FF input values are fixed, the fixed inputs become untestable and the fault detection rate drops. When implementing a scan design and converting to a scan FF, the scan may not be executed properl not be executed properly, so such descriptions , so such descriptions are not are not recommended. recommended.[1] As in the lower part of Example 2-21, be sure to construct a synchronous type of circuit and ensure that the clock signal is input to the clock pin of the FF. Other than the sample shown in Example 2-21, there are situations where for certain control signals, those that had been switched due to the conditions of an external input will no longer need to be switched, leaving only a FF. If logic exists in a lower level and a fixed value is input from an upper level, the input value of the FF may also end up being fixed as the result of optimization with logic synthesis tools. In a situation like this, while perhaps difficult to completely eliminate, the problem should be avoided as much as possible.
标签: RTL verilog hdl
上传时间: 2022-03-21
上传用户:canderile
目前电动汽车主要以锂电池作为动力来源,为了提高锂电池的使用时间和安全性,为锂电池提供安全良好的运行环境,电池管理系统应运而生。BMS主控单元基于S32K144汽车级单片机,通过主从式网络控制结构能够对锂电池的各个参数进行采集与分析。采用扩展卡尔曼滤波对电池的荷电状态(SOC)进行估算,克服普通估算方法无法避免电池内阻误差的缺点,通过Matlab/Simulink软件仿真验证可使估算误差达到2%以内。At present,electric vehicles mainly use lithium batteries as the power source.In order to improve the running time and safety of lithium batteries,a safe and good operating environment for power batteries is provided,and a battery management system(BMS) has emerged.The BMS main control unit is based on the S32K144 automotive-grade control chip.Through the master-slave network control structure,it can collect and analyze the various parameters of the lithium battery.The Extended Kalman Filter(EKF) is used to estimate the state of charge(SOC) of the battery,which overcomes the shortcomings of the internal estimation method that cannot overcome the internal resistance error of the battery.It can be verified by Matlab/Simulink software simulation.The estimation error is within 2%.
上传时间: 2022-03-26
上传用户:XuVshu
对某四轮独立驱动电动汽车轮毂电机进行研究,设计一种永磁无刷直流电机控制器.以STM32F103RBT6芯片为基础,对电机驱动电路、采样电路和保护电路分别进行硬件设计与分析;同时,采用模块化软件设计方案,对该控制器的软件系统进行升级.实验验证表明:所设计的电机控制器能使电机响应迅速、转速稳定、无超调,且电动车动力输出性能良好.A permanent magnet brushless direct current motor controller was designed by studying the hub motor of a four-wheel independent drive electric vehicle.Based on STM32 F103RBT6 chip,the hardware design and analysis of motor drive circuit,sampling circuit and protection circuit were carried out respectively.At the same time,modular software design scheme was adopted to upgrade the software system of the controller.Experimental results show that the designed motor controller can ensure the motor fast response,stable speed,no overshoot,and good power output performances.
上传时间: 2022-03-26
上传用户:qingfengchizhu
本文主要介绍如何在Wado设计套件中进行时序约束,原文出自 xilinx中文社区。1 Timing Constraints in Vivado-UCF to xdcVivado软件相比于sE的一大转变就是约束文件,5E软件支持的是UcF(User Constraints file,而 Vivado软件转换到了XDc(Xilinx Design Constraints)。XDC主要基于SDc(Synopsys Design Constraints)标准,另外集成了Xinx的一些约束标准可以说这一转变是xinx向业界标准的靠拢。Altera从 TimeQuest开始就一直使用SDc标准,这一改变,相信对于很多工程师来说是好事,两个平台之间的转换会更加容易些。首先看一下业界标准SDc的原文介绍:Synopsys widely-used design constraints format, known as sDc, describes the design intent"and surrounding constraints for synthesis, clocking, timing, power, test and environmental and operating conditions. sDc has been in use and evolving for more than 20 years, making it the most popular and proven format for describing design constraints. Essentially all synthesized designs use SDc and numerous EDa companies have translators that can read and process sDc
标签: vivado
上传时间: 2022-03-26
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本系统采用电动机电枢供电回路串接采样电阻的方式来实现对小型直流有刷电动机的转速测量。该系统主要由二阶低通滤波电路,小信号放大电路、单片机测量显示电路、开关稳压电源电路等组成。同时自制电机测速装置,用高频磁环作为载体,用线圈绕制磁环,利用电磁感应原理检测电机运行时的漏磁,将变化的磁场信号转化为磁环上的感应电流。用信号处理单元电路将微弱电信号转化为脉冲信号,送由单片机检测,从而达到准确测量电机的速度的要求。In this system, the sampling resistance of armature power supply circuit is connected in series to measure the speed of small DC brush motor. The system is mainly composed of second-order low-pass filter circuit, small signal amplifier circuit, single-chip measurement and display circuit, switching regulated power supply circuit and so on. At the same time, the self-made motor speed measuring device uses high frequency magnetic ring as the carrier, coil winding magnetic ring, and electromagnetic induction principle to detect the leakage of magnetic field during the operation of the motor, which converts the changed magnetic field signal into the induced current on the magnetic ring. The weak electric signal is transformed into pulse signal by signal processing unit circuit, which is sent to single chip computer for detection, so as to meet the requirement of accurate measurement of motor speed.
标签: 直流电动机
上传时间: 2022-03-26
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随着光伏发电系统快速发展,以及电动汽车充电桩的普及,传统的剩余电流保护器无法满足实际需求。介绍了一款B型剩余电流保护器,采用磁调制剩余电流互感器和零序电流互感器采集剩余电流。根据GB/T 22794—2017标准要求,可识别1 kHz及以下的正弦交流、带和不带直流分量的脉动直流、平滑直流等剩余电流信号。经信号调理电路将电压信号送到单片机进行采集和判断。通过试验测试,该样机在测试精度和速度上均符合国家标准的相关要求。The rapid development of photovoltaic power generation systems and the popularity of electric vehicle charging piles make the traditional residual current protective devices unable to meet the actual demand.This paper proposed a type B residual current protective device,which uses the magnetically modulated residual current transformer and the zero sequence current transformer to acquire the residual current.According to the requirements of GB/T 22794—2017,the type B residual current protective device can detect sinusoidal AC residual current of 1kHz and below 1kHz,pulsating DC residual current with and without DC component,smooth DC residual current and so on.The signal processing circuit sends the voltage signal to the MCU for acquisition and judgment.Through experimental tests,the device meets the relevant requirements of national standards in terms of test accuracy and speed.
标签: 电流保护器
上传时间: 2022-03-27
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以STC12C5A60S2单片机为控制核心,采用2.4G(JF24D)无线遥控模块进行无线发射与接收,设计了一种双电机遥控船模控制系统.该系统通过切换档杆实现前进后退,方向盘左右转动、暂停按钮等控制直流电机的正转、反转、暂停,使得电机驱动的遥控船模实现前进后退、左右转向、暂停等功能,有效解决了驱动功率小和船模之间相互干扰等问题,可广泛应用于遥控船模领域.Using STC12C5A60S2 single-chip microcomputer as the controller and 2.4 G(JF24D)wireless remote control module for wireless transmission and reception, a dual-motor remote control ship model control system is designed. The system realizes forward and backward by switching the gear lever. The steering wheel rotates left and right and the pause button controls the forward, reverse and pause of the dc motor. The remote controller of ship model driven by the motor realizes forward and backward, left and right steering, pause and other functions. The ship model control system can effectively solve the problems of small driving power and mutual interference between ship models, and can be widely used in the field of remote controller of ship model.
上传时间: 2022-03-27
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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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