In this work, we optimize the repetition scheme for ultra-reliable low latency uplink communications. We consider grant-free access in the frequency domain, where a user transmits multiple repetitions of a packet over shared subchannels in a single time slot. To save transmission energy and to decrease collision probability, we optimize the number of repetitions subject to the diverse reliability requirements. In our optimization framework, different users may have different reliability requirements and different active probabilities depending on the user services. The optimization problem turns out to be an integer-programming problem with high complexity. We design a low-complexity algorithm to solve the optimization problem. Simulation results show that the proposed scheme can save uplink transmission energy by 10 ~ 30% and can reduce the infeasible probability remarkably compared with the K-repetition scheme. The infeasible probability is defined as the probability that the reliability requirement cannot be satisfied with the given resources.
Optimization of Repetition Scheme for URLLC with Diverse Reliability Requirements
2022-06-01
418078 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch