城市移动数字电视地面广播的信道噪声模型

21世纪以来,中国的一些大城市先后开展了数字电视地面广播试验,并实现了车载移动接收数字电视.试验中发现:车载天线因时空限制难以避开干扰源,白噪声与脉冲相混合的噪波不断地影响着车载数字电视系统的接收效果.为了进行高效的传播信号覆盖规划,需掌握实际运行环境中数字电视地面广播信道的噪声情况.本文介绍了上海市内公共交通线上UHF频段内某个频道的平均噪声功率测量结果;通过对噪声功率概率累积分布曲线的回归分析,不仅获得城市中三个典型交通环境下该UHF频道的噪声系数模型,而且给出了频道噪声系数统计分布的上侧十分位数K倍方差值.

Mobile Digital Television Channel Noise Models for Urban Terrestrial Broadcasting

Since 21st century,the test service for digital TV terrestrial broadcasting has been successively carried out in some Chinese big cities,and bus commuters can watch TV programmes while traveling in the signal covered regions.In the trial,it has been found that the environment noise comprising two dominant and distinct components:white Gaussian noise and impulsive noise affects the reception of mobile TV on the vehicle continuously,and that when the equipped vehicle traces along the traffic courses,in a limited time and space,the TV antenna is not able to avoid the noise source from the environment.In order to plan high-effective DTTV signal coverage,it is necessary for engineers to foreknow the noise level of a DTTV channel in the real electromagnetic environment.This paper introduces the results of average noise power of a digital TV channel in UHF band on public transportation lines in Shanghai.Not only the noise fact models but also the noise factor K times variance deviation of its upper decile under three typical communication environments has been obtained through the analysis of nonlinear regression of cumulative distribution functions on the test results.