Channel estimation strategy for using LDM to deliver local content insertion in ATSC 3.0

Delivering local content in terrestrial digital TV (DTV) single-frequency-networks (SFNs) is of great interest to broadcasters, which can support business cases such as local news, location-based applications and targeted advertisements. The recently adopted Layered-Division-Multiplexing (LDM) technology offers a new solution to achieve high-throughput local content insertion from any transmitters, at anytime, and with flexible coverage areas. To achieve the high-throughput and flexbile coverage of the local services delivered using LDM, the receivers need to estimate the specific channel response corresponding to the trasnmitter emitting the desired local service. This is difficult to achieve in reality since the ATSC 3.0 standard does not provide an inherent mechanism to help receivers obtain separate channel estimates when receiving signals from different transmitters in SFN. This paper addresses this challenge and presents several channel estimation solutions at receivers to enable high-efficiency local content insertion within an ATSC 3.0 SFN. In addition, a novel channel separation algorithm is proposed to significantly reduce the performance degradation caused by the inaccurate channel estimate due to the deterministic co-channel interference.