中文摘要：

介绍了基于地面广播的层分复用（Layered Division Multiplexing，LDM）技术的研究与进展。采用层分复用技术可以在不同的接收环境下根据应用需求来选择不同的功率和不同的编码调制方式，能极大地提高频谱的利用率和使用灵活性，且可应用于多个不同的系统中。正是由于该技术的以上特点，层分复用技术被ATSC3．0的专家组选为下一代ATSC3．0标准物理层的核心技术之一，同时被2015年美国广播电视协会展选为最佳技术。首先介绍层分复用技术的初始思想——“云传输”的基本概念，进一步从层分复用系统框架方面，着重介绍层分复用技术在噪声与层闻干扰处理、帧结构设计、发射识别和信号消除等方面的设计方法，最后对层分复用技术为地面广播系统带来的性能提升进行了总结。

英文摘要：

The research and development of Layered Division Multiplexing （LDM） technology based broadcast television system is proposed. Thanks to supporting physical layer data streams with different power levels, channel coding and modulation schemes for different services and reception environments. Layered Division Multiplexing technology can greatly improve the spectrum utilization and flexibility. Recently, Layered Division Multiplexing has been adopted as the key technology for the next generation of ATSC PHY 3.0 standard and the best technology of the American Broadcast Television Association. In this paper, the concept of ＂cloud transmission＂ is first introduced. Then, starting from basic physical structure of LDM, the key designs of LDM system in noise and interlayer interference processing, frame designing, transmitter identification and signal canceling process is comprehensively introduced in this paper. Lastly, the performance improvement of terrestrial broadcast system brought by LDM technology is summarized.