5G New Radio LDPC Extensions for Multimedia Broadcast Multicast Service

Abstract

The 3rd Generation Partnership Project (3GPP) introduced the Further evolved Multimedia Broadcast Multicast Service (FeMBMS) transmission mode as an extension of the Long-Term Evolution (LTE) standard in 3GPP Release 14. FeMBMS enables the broadcast of services on a dedicated carrier and is currently being tested in numerous field trials worldwide. The New Radio (NR) air interface, standardized in 3GPP Release 15, introduced Low-Density Parity Check (LDPC) codes as a new forward error correction scheme, but does not yet support broadcast transmissions. The 5G NR standard is designed for unicast transmissions and only supports short codeword lengths.In contrast, the digital terrestrial television broadcast standards DVB-T2 and ATSC 3.0 both utilize LDPC codes with long codeword lengths as these have proven to increase the error correction performance of transmission systems.Similarly to FeMBMS, broadcast services based on 5G NR may be introduced in a future 3GPP release and would benefit from longer LDPC codeword lengths.The introduction of new codeword lengths into the 5G NR standard requires careful consideration of the existing coding procedures. After detailing the 5G NR LDPC coding chain, this paper presents a set of minimal extensions to the 5G NR standard required in order to realize longer LDPC codes. These extensions are evaluated and the achievable performance is compared to that of the LDPC codes standardized in the ATSC 3.0 specification.