Performance Characterization and Optimization of Mobile Service Delivery in LDM-Based Next Generation DTV Systems

Layered-division-multiplexing (LDM) technology is a non-orthogonal multiplexing technology to provide more efficient transmission of multiple services that have different requirements on the robustness and throughput in one TV channel. The core of LDM is to transmit multiple-layer signals, where each layer occupies the whole channel bandwidth and the whole time. To meet the different requirements on different layers, each layer is allocated a specific power level, and is configured to use a different channel coding and modulation scheme, as well as its own multiple-antenna technology. Delivering robust and high-quality mobile TV services is one of the top priorities for the next generation digital TV (NG-DTV) systems. In this paper, we first investigate the performance of the NG-DTV systems with LDM in various difficult propagation channels that are likely encountered by the large variety of mobile devices, including fast-fading channels, slow-fading channels, indoor channels, and single-frequency-network (SFN) channels. A new channel estimation technique is proposed to overcome the severe performance degradation caused by the SFN channels. We will further show that using LDM makes it possible to deliver mobile services using the efficient 32k transmission mode. Finally, receive antenna diversity is shown to provide different levels of performance improvement for different LDM configurations.