Superposition Coding for URLLC Services in a 4G/5G Cooperative System

摘要

URLLC services are very demanding in terms of quality of service (QoS). We study in this paper dual-connectivity as an enabler for ultra reliability and specifically consider combining 4G and 5G spectrum for delivering URLLC packets. We compare different dual connectivity schemes, including a best link selection scheme and a maximum ratio combining scheme. We consider first an outdoor scenario with users served by macro base stations, where 4G and 5G transmitters are co-localized, and show that ultra-reliability is difficult to achieve everywhere unless the network is densified, or packets are replicated. We then study an industry 4.0 scenario where UEs are localized within a factory and served by indoor 5G small cells, in addition to coverage from outdoor 4G base stations, and show that URLLC requirements are achievable in this scenario.