On Parallel Retransmission for Uplink Ultra-Reliable and Low Latency Communications

This paper introduces the concept of parallel transmission and proposes two novel retransmission schemes based on parallel transmission for uplink ultra-reliable and low latency communications. One scheme performs two transmission attempts over both dedicated and shared resources in the first transmission opportunity and the retransmission over the dedicated resource in the next one if necessary. The other scheme performs parallel retransmission over both types of resources if the initial transmission is unsuccessful. We formulate the system model to analyze the reliability and resource utilization of different retransmission schemes. Numerical results show that the proposed retransmission scheme has a higher reliability than existing ones. Moreover, one of the proposed schemes significantly uses less resource than other schemes.