Initial Steps Toward a Cellular Vehicle-to-Everything Standard [Connected Vehicles]

The Third Generation Partnership Project (3GPP) has developed some functionalities to provide enhancements of cellular standards specifically for vehicular communications. These include both direct communication (between vehicles, vehicle-to-pedestrian, and vehicle-to-infrastructure) and cellular communications with networks. The vehicle-to-vehicle (V2V) work item builds on earlier work on device-to-device (D2D) communications and introduces a new D2D interface (designated as PC5, which is also known as the sidelink at the physical layer), specifically addressing communications at vehicular speeds. To that end, four additional pilot symbols have been added to the demodulation reference signal to allow for better tracking of the channel despite high Doppler effects associated with relative speeds of up to 500 km/h and at high frequency (with 5.9 GHz ITS band being the main target).