Wireless In-Band Distribution Link using LDM for SFN Transmitters and Gapfillers in ATSC 3.0

Delivering services to mobile devices in densely populated indoor and enclosed areas, such as stadiums, airports, train stations, and shopping malls, has the potential to bring more viewership to terrestrial broadcast services. The next-generation ATSC 3.0 system is designed with extremely robust transmission capability to deliver high-quality mobile services to portable and handheld receivers. Even with the most robust transmission mode, delivering services to these indoor environments still proves challenging due to high penetration losses. One solution is to deploy low-power, single frequency network (SFN) transmitters, called SFN Gapfillers, which can provide reliable mobile services specifically to indoor/enclosed areas. In deploying SFN Gapfillers, a significant cost derives from the service data distribution link. In this paper, we propose a wireless, in-band distribution link using Layered Division Multiplexing (LDM) technology. Instead of dedicated fiber or microwave links, in the proposed solution, the service distribution-link data is delivered to the SFN Gapfillers with a high-power transmitter, using the Enhanced Layer of a two-layer ATSC 3.0 signal, which results in low infrastructure and operational costs. By using LDM, the wireless distribution links are implemented with high spectrum efficiency since they share the same TV band with the broadcast services. To guarantee successful SFN operation of the Gapfillers, sufficient delay of the broadcast service signal from the SFN distribution signal is required. The proposed technology also can be applied to deploy conventional SFN transmitters to extend coverage areas or to provide services to remote areas.