通信系统

A software HF channel simulator based on Watterson model was presented according to the characters of multipath, fading, Doppler frequency shift and Doppler frequency spread in HF channel.

对短波信道多径、衰落、多普勒频移及扩展等现象进行了分析，并且基于Watterson离散信道模型，设计了一种全软件的短波信道模拟器，为短波通信系统性能测试提供了条件。

The increasingly demanding performance requirements of communications systems, as well as problems posed by the continued scaling of silicon technology, present numerous challenges for the design of frequency synthesizers in modern transceivers.

通信系统的性能要求越来越苛刻，以及由硅技术不断提升，为在现代收发器频率合成器的设计带来许多挑战造成的问题。

In the third system, the main method of multiple access is wide band code division multiple access.

第三代数字移动通信系统多址方式的主流为宽带CDMA技术。

In the system of communication ,the useful signal is picked up from noise by the technology of adaptive filtering. It will have the wide applicative prospect .

在通信系统中，采用合适的自适应滤波技术，从被污染的信号中提取有用的信号有着广阔的应用前景。

The invention relates to a method for information transmission in a coexistent wireless communication system and a device thereof.

本发明涉及一种共存性无线通信系统中的信息传输方法及装置。

In this paper,based on the convolutional codes,it analyzes the principle of error-correcting codes.

在现代数字通信系统中，纠错编码技术的作用是很重要的，本文以卷积码为例，分析了纠错码的原理，并利用matlab实现了卷积码的编码和解码，对卷积码纠错原理进行了仿真研究。

A method and apparatus for improving the performance of a convolutional encoder used in a slotted mode communication system.

一种改进在时隙模式通信系统中使用的卷积编码器性能的方法和设备。

In this paper, we give the simulation results of bit error rate based on group counterchange method for BCH codes in UWB communication system in the condition of AWGN channel.

本文给出了群变换方法构成的BCH编码在超宽带通信系统中的误码率仿真结果。

CH10,CH12 and CH15 materlals,which show lower disaccommodation and higher stbility over a wide range of temperatures, can be applied in the ADSL technology of internet telecolnmunication System,Which can greatly increase transmission velocity and distance and reduce THD of signals

CH10、CH12、CH15材料还具有宽温、低减落、高稳定性特征，用于网络通信系统ADSL技术，可大大提高传输速度和传输距离，减少信号的谐波失真THD。

Tesla's wireless and communications system did not use Hertzian waves to broadcast but rather used the EARTH as a carrier for the electromagnetic and high frequency waves.

特斯拉的无线通信系统和没有使用赫兹波广播，而是使用了地球承运人的电磁和高频波。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。