Ma, H., Zhang, E., Li, S., Lv, Z. et al., "A V2X Design for 5G Network Based on Requirements of Autonomous Driving," SAE Technical Paper 2016-01-1887, 2016, doi:10.4271/2016-01-1887.
Today it is already practically feasible to consider fully automatic operation of vehicles in restricted areas. The character of V2X service used in autonomous driving can be described as low latency, high reliability, high traffic and high mobility. In this paper we give a V2X design for 5G network to support autonomous driving. The design target is to achieve as low as 1ms delay between user planes of air interface, 99.999% air interface reliability through retransmissions limited in 10ms duration, at least 2000 vehicles per kilometer for low speed, 200 vehicles per kilometer for high speed, 50Mbps cell edge throughput for V2I, and 10Mbps rate for V2V. Using LTE Advanced as a baseline, we do some enhancements on network architecture, system frame structure, physical channels, and system procedure. More specific, we propose a novel frame structure which contains 20 subframes and 0.5ms duration for each subframe to fulfilled the 1 ms delay requirement, a optimized reference signal settings to reduce processing delay, a network architecture fusing cell merge, cell split, and local MBMS to cope with high traffic volumes and high mobility, and a V2V transmission scheme based on D2D enhancement. Simulation results show that the low latency design we proposed can effectively improve the delay performance of legacy LTE, which may be a good choice to meet the autonomous driving requirements on latency, reliability, traffic and mobility metric.