Adjacent Channel Interference Analysis From U-NII-4 and U-NII-5 Devices Into 5G NR V2X Devices

The Federal Communications Commission in the U.S. assigned 30 MHz from the 5895-5925 MHz band for vehicular communication. Adjacent bands, i.e., from 5850-5895 MHz and 5925-6425 MHz, were designated for unlicensed devices. In this study, the effect of adjacent channel interference (ACI) from unlicensed devices into 5G new radio (NR) vehicle-to-everything (V2X) devices was investigated at the link and system level simulations. After conducting link level analysis, a downtown congested traffic scenario with 330 vehicles was considered at the system level. An unlicensed device was assumed to operate using either IEEE 802.11ac or 802.11ax standard. At the link level, only the ACI from a U-NII-4 device degrades the performance of 5G NR V2X devices. At the system level, the ACI from U-NII-4 device with 90% duty cycle degrades the performance by 2.5 dB while for all other cases, a single unlicensed device does not affect the 5G NR V2X performance because it is obscured by the interference from the other 5G NR V2X devices using the same subchannels.