Improved Semi-Blind Channel Estimation With Time Domain Cancellation for LDM-LSI

The adoption of OFDM as the physical layer waveform in ATSC 3.0 leaves the door open for the implementation of Single Frequency Networks (SFN). In addition, Layered Division Multiplexing (LDM), which can be understood as a low complexity approach for Non-Orthogonal Multiple Access (NOMA) techniques, has also been included as a baseline technology. These two new features can be combined to offer LDM based Local Contents (LC) in SFNs with unprecedented spectrum efficiency. Up to now, the design of a reliable channel estimation algorithm that does not require any modification of the standard has been the main challenge for the successful development of this approach. This paper aims at providing tools for satisfactory and efficient application of LDM-LSI (Local Service Insertion). In particular, in this paper, three major contributions are presented: a new semi-blind channel estimation algorithm that takes advantage of the LDM structure of the network, a time domain cancellation technique for NOMA, and the implementation of the proposed solution in a fully compliant ATSC 3.0 transceiver.