Primary Synchronization Signal for an Orthogonal Time Frequency Space Based 5G Broadcast System

Recent advancements in Long Term Evolution (LTE)-based 5G Terrestrial Broadcast have significantly improved physical layer performance, particularly for large-area coverage. Built on the LTE standard, this technology uses Orthogonal Frequency Division Multiplexing (OFDM), which is well-suited for multipath environments. Traditional LTE unicast uses OFDM numerologies that restrict the cell radius to about 5 km. To achieve broader coverage in High Power High Tower (HPHT) broadcasting configurations, modified OFDM numerologies are necessary. However, these numerologies continue to present stability challenges when simultaneously accommodating wide coverage areas and high mobility. Orthogonal Time Frequency Space (OTFS) modulation offers a potential solution, as it is resistant to high Doppler shifts. This paper explores synchronization strategies in a possible extension of today's LTE-based 5G Terrestrial Broadcast system using OTFS modulation. We focus on the Primary Synchronization Signal (PSS) for OTFS carriers and detail a method to map the PSS into an OTFS frame in the time domain, enabling correlation-based synchronization. Simulations demonstrate the robustness of this synchronization approach. The paper concludes with an outline of the results and proposes directions for future research.