Gray-Mapped NOM-Enhanced SFN: A Broadcast and Broadband Converged Transmission Solution in LTE-Based 5G Broadcast

Broadcast and broadband converged transmission has emerged as a prominent research focus within broadcast technology. Abundant corresponding studies have been conducted in traditional terrestrial broadcast and 3GPP unicast systems. However, due to issues like system compatibility, traditional terrestrial broadcasts usually reveal insufficient flexibility in transmitting broadband services, and conventional unicast systems always perform inefficiently in delivering broadcast services in scenarios of converged transmission. In addition, as the current Non-Orthogonal Multiplexing (NOM) scheme employed in converged transmission usually does not comply with the Gray-mapping rule, the required codeword-level Successive Interference Cancellation (SIC) algorithm makes the Enhanced Layer (EL) data share the same processing delay as the Core Layer (CL) one, which restricts the variety of EL services. This paper focuses on the physical layer technologies of converged transmission in the 3GPP LTE-based 5G Broadcast system. Due to the inherent good compatibility with both broadcast and broadband systems, LTE-based 5G Broadcast has great potential in realizing the converged transmission of broadcast and broadband. In addition, a novel converged transmission scheme enhanced by Gray-mapped NOM is proposed in this paper, and the corresponding networking architecture, frame structure, transmitting processing, and receiving algorithms are put forward. By significantly improving the performance of the non-SIC receiving algorithm, the proposed Gray-mapped NOM-enhanced SFN (GNeSFN) scheme enables the EL customized services and the CL broadcast services to have processing delays independent from each other, bringing more flexibility to converged transmission. Link-level simulations are carried out with different system configurations and multiple channel scenarios, verifying the effectiveness and feasibility of the proposed scheme.