工频

For orthogonal frequency division multiplexing systems in high-mobility environment, channel variations within one OFDM symbol will introduce intercarrier interference, thus lowering the system performance.

对於应用於高移动通讯环境之正交分频多工(Orthogonal Frequency Division Multiplexing， OFDM)系统，每一个OFDM符元期间的通道时变导致载波间干扰(Inter-carrier Interference， ICI)发生，使得系统效能降低。

In anFDD wireless system, the duplex spacing between uplink and downlink islarger than the coherence bandwidth of the mobile radio channel, thus theuplink and the downlink small-scale fading is uncorrelated. Moreover, thearray response is correlated with the frequency of the signal carrier. So it isimpossible to resue the uplink weights for downlink beamforming. As aresult, the application of smart antenna for the downlink is a difficult problem.

在频分双工系统中，由于上、下行载波的频率差大于相干频带，上、下行信道衰落是不相关的，而且阵列响应也与信号的载波频率有关，因此，上行信道不能直接用来估计下行信道，故智能天线应用于下行链路是一个难点。

The spectrum is achieved from the locale vibration signal applying Local Wave Method, on which the state-feature table of the system is established. Then the feature group with the maximum of fault information is worked out, the fuzzy tree is established sequently.

对往复压缩机振动信号进行局域波时频处理，得到包含故障状态值的局域波时频谱，结合系统工况资料建立系统故障状态一特征表，找出最大故障信息量的特征群，建成故障信息量的模糊二元树。

A small scale digital trunking communication system based on the spread spectrum technology was presented.

介绍了一种基于扩频技术的全双工通信小型集群通信系统。

It suggests that for the same circumstances (3.5MHz frequency-division duplex, 3.5GHz band), adding subchannelization, diversity and space-time coding to a base station could increase the coverage range from 2km to 9kma twentyfold increase in coverage and, potentially, in subscribers.

文中提出，对相同的环境(3.5-MHz频分双工、3.5-GHz频带)，在一个基地台中增加子讯息通道化、多样化和空-时编码(Space-time coding)可以把覆盖距离从2公里提高到9公里，覆盖率增加20倍，这意味著潜在用户也增加20倍。

Shangyu haoxiang communication technology co.,ltd is tries research and develop the production sale microwave radio frequency passive companent's specialized company,the main product including the merit minute coupler electric bridge load attentuater filter diplexer mixer and so on,this company produces with the debugging uses the advanced HP/agilent vector network analyzer,the company has many kinds of high low temperatures,the shake table,test spare parts and the product and so on salt-fog test box reliability equipment.

上虞豪祥通讯科技有限公司着力研发生产销售微波射频无源器件的专业公司，主要产品包括功分器，耦合器，电桥，负载，衰减器，滤波器，双工器，合路器等，本公司生产和调试都采用先进的HP/Agilent矢量网络分析仪，公司拥有多种高低温，震动台，盐雾试验箱等测试零部件和产品的可靠度的设备。

Four 8-bit I/O Ports C Three 16-bit Timer/Counters C 256 Bytes Scratch Pad RAM C 8 Interrupt Sources with 4 Priority Levels C Dual Data Pointer Variable Length MOVX for Slow RAM/Peripherals High-speed Architecture C 10 to 40 MHz in Standard Mode 16K/32K Bytes On-Chip ROM Program T80C51RD2 ROMless Versions On-Chip 1024 bytes Expanded RAM C Software Selectable Size (0, 256, 512, 768, 1024 bytes) C 256 Bytes Selected at Reset for AT87C51RB2/RC2 Compatibility Keyboard Interrupt Interface on Port P1 8-bit Clock Prescaler 64K Program and Data Memory Spaces Improved X2 Mode with Independant Selection for CPU and Each Peripheral Programmable Counter Array 5 Channels with: C High-speed Output C Compare/Capture C Pulse Width Modulator C Watchdog Timer Capabilities Asynchronous Port Reset Full Duplex Enhanced UART Dedicated Baud Rate Generator for UART Low EMI Hardware Watchdog Timer (One-time Enabled with Reset-out) Power Control Modes C Idle Mode C Power-down Mode C Power-off Flag Power Supply: 2.7V to 5.5V or 2.7V to 3.6V Temperature Ranges: Commercial (0 to +70C) and Industrial (-40C to +85C) Packages: PDIL40, PLCC44, VQFP44

四8位I / O端口C款三16位定时器/计数器 256字节RAM的便笺簿 8中断源4优先级和C双数据指针MOVX在缓变长内存/外设高速架构为C 10至40 MHz的标准模式16K/32K字节的片上ROM程序T80C51RD2无ROM版本片1024字节扩展RAMC软件可选尺寸（0，256， 512，768，1024字节）C选取在重置为AT87C51RB2/RC2兼容键盘中断接口与独立的选择港口小一8位时钟分频器64K的程序和数据存储器空间的改进X2模式的CPU和256字节每个外设可编程计数器5通道的阵列：C型高速输出C比较/脉宽调制器捕获看门狗定时器复位功能异步端口全双工增强型UART的波特率发生器的UART低EMI硬件看门狗定时器电源控制模式空闲模式C掉电模式C断电旗电源：2.7V至5.5V或2.7V至3.6V温度范围：商业（0到+70 C）和工业（- 40C至+85℃）封装：PDIL40，PLCC44，VQFP44

Moreover, we use the new concept to design a novel microwave circuit called Tri-duplexer, which composites both the capability of the Triplexer and the duplexer.

而这个新型的微波电路，我们称为三频双工器。

Four new microwave devices revolutionized radar; the British Magnetron (optimized and fanned out into a family by BTL/Western Electric), the American gas discharge duplexer transmit-receive T-R switch tube, the American advanced semiconductor mixer diode (MIT Rad Lab and BTL/WE), and the American klystron local-oscillator tube.

四种新型的微波装置掀起了雷达发展的革M：英国磁控管（为贝尔电话实验室和Western Electric所改良并发展成为一个大家族），美国的气态双工收发转换开关，美国的先进半导体二极管混频器(MIT 电子实验室和 BTL/WE)和美国的可调速本机振荡管。

Design and simulation results show that these two kinds of 3 dB-couplers are consistent with general requirements of parameter indexes, and can be respectively suitable for narrowband and broadband in the adjacent-channel duplexers.

设计和仿真结果表明，这两种结构的三分贝耦合器符合一般的指标要求，分别适用于窄带和宽带的数字邻频双工器中。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷