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1 江门市光纤CATV系统概况 地处珠江三角洲的江门市是广东省著名侨乡,新兴工业城市,城市人口40余万。在光纤CATV系统建设前,该市已有一个以电缆为传输媒介的有线电视系统,完成了市区内部分地区的联网,播送近10个频道的电视节目。但由于设备性能和电缆老化失效等原因,致使部分电视频道载噪比和交扰调制比、互调比指标明显下降,部分电视频道图像有较明显的噪点、雨刷干扰、网纹干扰等现象。
1 Jiangmen Fiber Optic CATV System Overview Located in the Pearl River Delta Jiangmen City is a famous hometown of overseas Chinese in Guangdong Province, a new industrial city, urban population of 400,000. Before the construction of optical fiber CATV system, the city already had a CATV system with cable as the transmission medium, completed the networking in some parts of the urban area and broadcasts the television programs of nearly 10 channels. However, due to equipment performance and cable aging failure and other reasons, some television channel carrier-to-noise ratio and crosstalk modulation ratio, intermodulation indicators decreased significantly, some of the TV channel images have more obvious noise, wiper interference, moire interference and so on.