Uplink reference signals enabling user-transparent mobility in ultra dense networks

This paper proposes a novel user-transparent mobility concept based on the transmission of uplink reference signals (beacons) using Zadoff-Chu signature sequences. Unlike legacy mobility schemes, the proposed scheme overcomes the need for the user to perform time and energy consuming downlink measurements and reporting them back to the network. This is particularly relevant for ultra dense network (UDN) deployments and high user densities as forecasted in the near future. The system requirements to support uplink beacons are presented and a detailed design for the signature sequence is provided to support a variety of system configurations and deployment cases. Numerical results illustrate the suitability and sufficiency of beacon resources as well as the reliability of the proposed beacon design in order to support a truly user-transparent and border-less mobility concept.