论文部分内容阅读
大功率无线电台、输电线路和电气化铁路,以及其他通信线路强电磁场源所引起的外部干扰,可导致对称电缆线路的质量和可靠性显著恶化。尽管多年来一直尽力寻找防止上述干扰的各种方法,但是要将其降低到所要求的标准值,这仍然是一个迫切的问题。此外,在上述干扰的影响下还发现数字传输系统的线路工作中断,而仅仅由于广播台站的影响就会使音频信道的损耗(在模拟传输系统中)超过1％。解决上述问题的复杂性决定于受影响的信道参数的稳定性,以及导致干扰增加的其他大量因素。列宁格勒通信工程学院进行的研究表明,在绝大多数情况下无线电干扰增加的原因有:“接触不良”型
External interference caused by high-power radio stations, transmission lines and electrified railways, and other sources of strong electromagnetic fields from communication lines can lead to significant deterioration in the quality and reliability of symmetrical cable lines. Although various attempts have been made to find ways to prevent such disturbances over the years, it is still an urgent matter to reduce them to the required standard value. In addition, under the influence of the aforementioned interference, it was found that the digital transmission system was interrupted by the line work, and the loss of the audio channel (in the analog transmission system) exceeded 1% only due to the influence of the broadcasting station. The complexity of solving the above problem depends on the stability of the affected channel parameters and on a number of other factors that lead to increased interference. Studies carried out by the Leningrad Institute of Communication Engineering show that the increase in radio interference in the vast majority of cases is due to the “poor contact”