An Access Priority Level Based Random Access Scheme for QoS Guarantee in TD-LTE-A Systems

The Quality of Service (QoS) requirement of Random Access Procedure (RAP) emphasizes on success ratio and access delay in TD-LTE-A systems. In some applications like urgent communications, User Equipment (UE) will be labeled with different priority level. High priority UEs are critical to system implementation. In this paper, we proposed an Access Priority Level Based Random Access Scheme (APL-RA) in order to provide the access QoS guarantee for high priority UEs. The proposed scheme combines preamble split and backoff algorithm in access procedure to realize different priority level UEs random access for TD-LTE-A systems. The simulation results showed that the proposed scheme has better performance in high level priority UEs scenario, comparing with the conventional random access scheme. Also, it has little overhead and can be smoothly embedded in TD- LTE-A systems.