有线信道

自由空间光通信是以激光作为信息载体，是一种不需要任何有线信道作为传输媒介的通信方式。

Free-space laser communication with laser as information carrier is a communication method which does not need any wired channel .

常规DCS系统的通信网络主要采用有线信道（如光缆、电缆等）构成数据链路，但在许多情况下，采用无线组网方式会具有更大的优势。

The communication network of conventional DCS mainly uses wired channels , such as twisted pair wire or optical fiber , but under some circumstances the wireless DCS will be a better solution .

无论是无线信道还是有线信道，在使用前都需要对信道特性进行仔细研究，以期最大限度的利用信道资源进行通信。

Both radio channel and cable channel , it will be right before using the channel characteristics of careful study in order to maximize the use of channel resources to communicate .

与传统有线信道相比，低压电力线信道的时变特性和强干扰特性使之在数据通信时误码率较大、可靠性不高。

The temporal variation and powerful interference of low-voltage power line channel , which had high bit error rate and low reliability when data were transmitted compared with the traditional line channel .

介绍了数字电视信号在有线信道中传输和接收所需的信号处理方式以及数字接收终端和模拟接收终端各自所需的解调、解扰、解密的方式方法。

The paper introduces the processing and transmission models of digital TV signal in the cable channel concerned with demodulation and decoding models of digital TV signal for digital TV and analog TV .

信号在无线信道中传播时，遭受到干扰、衰落和由移动台的运动引起的多普勒扩展等效应，都使它与有线信道相比要更为复杂。

Signals transmitting through the air often suffer from interference , fading , and the Doppler spread caused by the movement of both mobile stations and the scatters . Therefore , radio channels are more complex than wired channels .

由于无线信道不像有线信道那样固定并可预见，而且具有很大的随机性，甚至移动台的速度都会对信号的衰减产生影响，因此，使得无线信道难以分析。

Unlike the cable channel is fixed and predictable , the wireless channel is random , even the speed of the mobile station will reflect on the attenuation of the signal level . Therefore , the wireless channel is very difficult to analyze .

无线信道比有线信道有着更大的随机特性，从而导致接收信号幅度的衰减，相位和频率的失真，对接收机的性能提出了很大的挑战。

What is different from cable channels is that wireless channel has a lot of randomness , and it results in the attenuation of received signal amplitude , phase distortion and frequency distortion , so this is a great challenge in the performance of the receiver .

本系统可以用于有线电视信道中各种数字传输方式的研究，稍加修改也可以作为有线电视数字机顶盒或电缆modem系统的调制发送模块。

The system can be applied to CATV shell or modulation transmission module of cable modem .

基于美国数字有线电视标准信道解码技术的DSP实现

DSP Implementation of Channel Decoding based on American Digital Video Transmission Standard for Cable Television

有线数字电视信道接收芯片的实现研究

Research on the Realization of the Channel Receiving Chip in Cable DTV

通过GPRS与传统有线、无线通信信道之间的对比得出应用GPRS的优点。

This article mainly concerned the following two parts : 1 . Application of GPRS : Prove the advantage of using GPRS by comparing it with traditional wire / wireless channels .

在数字电视传输过程中，信道传输质量与效率是影响数字电视产业发展的重要一环，而信道编码的优劣直接影响有线电视信号在信道中的传输质量与效率。

And , the transmission quality and efficiency of digital TV signal effects the television industry development , but channel coding quality directly influence transmission quality and efficiency .

但是，在无线网络环境中，信道的误码率远远高于有线网络，由于信道原因而产生的丢包现象频繁发生。

However , in wireless networks , the channel bit rate error is much higher than that in wired networks . Many packet losses may be due to the channel error .