The Study for Monitoring CATV Signal

• Main Authors: Chi-Ming Teng, 鄧淇明
• Other Authors: Rong-Seng Chang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/f99qej

碩士 === 國立中央大學 === 光電科學與工程學系 === 102 === In general, when audience watch TV programs, TV screen had been interfered, and it resulted in distortion of the image screen, like snowflakes, ghosting and other noise distortions, the distortion generation is transmitted by a transmission device of program sources, such as head-end equipment to the client, resulting in TV video quality is not clear, which affect the signal performance. So signal owns a very important impact in the CATV field. It is to use the power level in the signal strength measurements to detect tolerance on CATV agency or cable set-top box manufacturer, whether within the specified range of specifications to determine the image quality is good, but this measurement method is not reliable to ensure that there is interfered signal in the glitch image distortion or noise caused distortion. Therefore, we want to design a CATV system to monitor cable source in this experiment. The experiment use a spectrum analyzer hardware and Labview program that write a program to monitor cable TV signals, and the monitoring CATV systems can analyze the causes of noise and it provides research reports to improve signal quality, and finally, we use it to verify that the monitoring system is perfect by the carrier signal picture and VM700 video test pattern analyzer. Contribution for these experiments, the first, it is the ability to provide automated monitoring of signals and signal noise analysis capability. The second, it is to provide real-time information to analyze the relationship between the observed signal and noise, in order to provide direction to improve the quality of the TV screen video. The third, it is to provide CATV agency to setup signal source device, and it provides more reliable and effectiveness measurement tools. The contributions in the future, it provides automatic correction can be expected to reach capacity in the future through the signaling system of the CATV signal reports. And provide future image recognition on the image, you can determine good and bad signals, as well as monitoring systems with the ability to provide future optical communication devices, you can analyze optical signal cable. Keywords: Cable TV signal monitoring systems, cable communications theory.