查询词典 frequency channel

However, for the wireless mobile communication systems, the radio channel is frequency selective and time-varying.

对于无线通信系统，无线信道不仅是频率选择性的，而且是时变的。

In a multipath radio channel, frequency selective fading can result in large variation in the received power of each carrier.

在一个多路径收音机频道中，选择的时尚频率能造成每个运送者的被一般承认力量的大变化。

Its final target is to fully digitize the analogue receiver. The all digital receiver not just means digitizing every unit of the analogue receiver, but is a new receiver architecture. The two outstanding characters of this new architecture is: 1 It uses a high stable oscillator to generate a fixed frequency source. And both the sample signal and the local carrier required are obtained from it. 2 Once the received signal has been sampled by a high speed A/D converter, some digital signal processing algorithms will be used to realize all further processes, such as digital down-converting, match filtering, symbol timing, channel equalizing, carrier synchronizing, demodulating and decoding.

全数字接收机并不是简单地将传统的模拟接收机中所有的部件数字化的结果，而是一种全新的接收机体系结构，这种新的体系结构具有两个最为突出的特点：1）采用高稳定度晶体振荡器产生一个固定的本地频率源，接收机中所需的采样时钟信号和本地载波均从这一固定频率源得到；2）接收信号一旦经过高速模数转换后，余下的工作如频率变换、匹配滤波、定时同步、信道均衡、载波同步、符号解调、判决与译码等全部由数字信号处理算法来实现。

The previous researches have been done experiments mostly in the Water tank. In order to simulate turbulence of flow in river and research its characteristics, the characteristics of turbulence are studied by experiments in the water channel with ADV technique. The research results indicate that R.M.S. velocity linearly relates to the oscillating-grid frequency; R.M.S. velocity decays by power exponent relates to the distance from the grid midplane; and the relationship between the geometrical factors and the free movement space of water is direct proportion.

以往研究大都在水箱中对振动格栅紊流特性进行实验研究，为能模拟天然河道中的紊流，研究天然河道中紊流特性，利用ADV技术在水槽中对振动格栅紊流进行了实验研究研究结果表明：均方根速度与格栅振动频率成线性关系；均方根速度与距格栅中平面的距离成幂指数关系衰减；几何系数与水的自由运动空间成正比关系。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。