Radio Access Protocols with Multi-User Detection for URLLC in 5G

Inhalt:
In this paper we present collision-free and contention-based radio access protocols for sporadic small data packet transmissions in the 5G uplink. We compare them by computer simulations with respect to throughput, latency, and final negative acknowledgement (NACK) probability. Based on the performance evaluation results, we analyze the tradeoff between the number of transmission attempts of a packet and advanced collision resolution methods. Moreover, we investigate the impact of multi-user detection on the protocol performance. The key outcome of our study is that contention-based radio access protocols combined with multi-user detection are well suited for ultra-reliable low-latency communications (URLLC), providing error rates down to 10-5 in a low traffic load scenario.