说明：  这是国家数字电视广播标准的详细描述，是实验室的内部资料，网上很难找到的，希望对研究数字电视地面广播的朋友有用
(This is a detailed description of the national digital television broadcast standard, the laboratory' s internal data, the Internet is difficult to find the hope that a friend of the digital terrestrial television broadcasting)