Deploying 5G Broadcast in UHF Spectrum 

We describe how to deploy 5G Broadcast—a technology built on the LTE air-interface backbone—in the broadcast UHF spectrum, with a different channelization from cellular systems. LTE-based systems have classically had channelization in segments of 1.4, 3, 5, 10, 15 and 20 MHz, none of which are an exact match for channels in the broadcast UHF spectrum, which have typical channelization in segments of 6, 7 or 8 MHz. We first describe how new supportable channel bandwidths for the physical multicast channel (PMCH) were added to the 5G Broadcast standards, while minimizing the changes necessary to the 5G Broadcast synchronization signals and the bandwidths associated with these. Specifically, we describe how a small, backwards-compatible bandwidth for the synchronization signals (transmitted in the Cell Acquisition Subframes, CASs) were leveraged to indicate a larger, UHF-compliant bandwidth for the PMCH. We then describe the physical layer signals and parameters—such as the reference signals (RSs) and Transport Block Sizes (TBS)—that were adapted in accordance with the new PMCH bandwidths, followed by a discussion on higher-layer signaling via Radio Resource Control (RRC) that was necessary to configure these new PMCH bandwidths. We then highlight the subsequent addition of the broadcast UHF bands (with respective band numbers) to the 3GPP RAN4 specifications, that were crucial in facilitating broadcasters to deploy 5G Broadcast in their allocated spectrum.

Ayan Sengupta, Javier Rodriguez Fernandez, Alberto Rico Alvarino | Qualcomm Technologies Incorporated | San Diego, Calif., United States
Thomas Stockhammer | Qualcomm CDMA Technologies GmbH | Munich, Germany