短波

Air China has developed on its own the operation management system, integrated satellite telephone system, space data communication system and shortwave wireless system, which made it the first airline company with the super long-distance supervision capacity in the country. In 2004, after the use of shortwave communication systems, the supervision network which has Beijing and Lhasa as the core, covers the Asian continent, the Indian Ocean and Pacific Ocean stretching to the arctic pole area.

国航自行研制开发了运行管理系统，集成了卫星电话系统、空地数据通讯系统和短波无线电系统，使国航成为国内第一家具有超远程监控能力的航空公司，尤其是2004年短波通信系统的投入使用，形成了以北京、拉萨两点为圆心，全方位、全时空、全天候覆盖亚洲大陆、印度洋和太平洋，并延伸到北极区域的监控网络。

Firstly the basic principle of OFDM and its anti-multi-path-fading are briefly introduced in this paper. Then basing on this point, we researched the basic principle, the coding designing and the algorithm of the signal detection of these MIMO-OFDM systems. At the same time, the performances of STBC-OFDM and SFBC-OFDM were analyzed and simulated under short wave circumstance, and got some useful conclusions, they have certain reference value for more research of short wave communication in future.

本文首先介绍了OFDM系统的基本原理以及它对抗多径的基本原理，然后在此基础上，对其所形成的几种MIMO-OFDM系统的基本工作原理，码字设计以及相应的信号检测算法进行了研究，详细分析研究了STBC-OFDM和SFBC-OFDM系统的性能并在短波信道下对其性能进行了仿真和对比分析，得出了有用的结论，这对以后短波通信的深入研究具有参考价值。

A shortwave heating rate model of the aerosol atmosphere is established in consideration of the effects of atmospheric aerosol and absorbing gases on the solar radiation under conditions of cloudlessness. The shortwave heating effect of the winter aerosol in Lanzhou is studied by using this model.

综合考虑无云天气条件下，气溶胶和大气中各种吸收气体对太阳辐射的影响，建立了一个气溶胶大气的短波加热率模式，研究了兰州冬季气溶胶的短波加热效应。

A new detection of telegraphic signal in short-wave channel is presented. It is based on the discrete Gabor spectrum analysis.

针对电报用单频信号的持续时长来携带报文信息及短波信道易于受到噪声污染的特点，研究了短波电报信号的离散Gabor谱检测方法。

The "NVIS"(Near-Vertical Incidence Sky wave) antenna is set on the horizon, which can clear up the dead zone of short-wave communication, and a ferrite loading spiral coil antenna is installed on the rocker projectile to receive the short wave signal.

在地面设置近垂直入射天波传播"NVIS"天线，消除短波通信静区，弹上安装铁氧体加载螺旋线圈天线接收短波信号，利用原有弹载计算机进行数据处理。

By measuring the instantaneous value of short-wave spectrum, we can get an important parameter of the local ionosphere, foF2, and then work out the MUF of the electrocircuit.

通过对测试结果进行统计分析可以得出：短波频谱的一阶矩ICF和电离层F2层临界频率f0F2具有很好的相关特性，通过测量短波频谱的瞬时值可以得到本地电离层的重要参量f0F2，进而可以计算出电路的最高可用频率。

On the basis of setting up a model of the parallel transmission link of short-wave data communication system, this paper analyses the anti-noise performance of data communication in a non-selective Rayleigh gradually fading ionosphere channel, and derives the average error code rate formular and its curves.

在建立并发制短波数据通信系统模型的基础上，分析了非选择性瑞利慢衰落电离层信道中数据通信抗噪声性能，并导出了平均误码率公式，生成了误码率曲线，为雷达情报短波数据通信链路的仿真及效能评估提供理论依据

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。

This paper introduces a type of shortwave MODEM software program applied in a semiduplex SW transmitter-receiver, analyses the realization of communication between SW MODEM and computer serial port and thoroughly relates several key techniques of communication.

介绍一种用VC ++创建的动态链接库DLL ，应用于收发一体半双工短波电台的短波MODEM软件编程，并分析短波MODEM与计算机串口通信实现的方法，详细阐述其通信编程中几个关键技术。

Especially in military affairs, it is the vital part in military operations. Short-wave communication is attractive because only little power and proper expenditure is needed when it is used for long distance communication. For this valuable trait, many country have expanded the area of short-wave communication's research, thus there has become more and more new-model communication system.

短波通信之所以能吸引用户用它传递信息，最基本的原因是由于进行远距离通信时，仅需要不大的发射功率和适中的设备费用，这一宝贵的优点，使得世界各国近年来加紧了短波通信的研究，出现了各种新型的短波通信系统。

But in the course of internationalization, they meet with misunderstanding and puzzlement.

许多企业已经意识到了这一点，但在国际化的进程中，仍存在一些误区与困惑。

Inorder toaccomplish this goal as quickly as possible, we'll beteamingup with anexperienced group of modelers, skinners, and animatorswhosenames willbe announced in the coming weeks.

为了尽快实现这个目标，我们在未来数周内将公布与一些有经验的模型、皮肤、动画制作小组合作。