  5G new radio (NR) technology is introduced to satisfy more demanding
services. Ultra-Reliable Low Latency Communication (URLLC) requires very low
delay compared with the previous techniques. This is hard to achieve when
hybrid automatic repeat request (HARQ) is applied and especially when the
feedback channel is erroneous. In this work, we consider various delay
components in incremental redundancy (IR) HARQ systems and minimize the average
delay by applying asymmetric feedback detection (AFD) and find the optimal
transmission length for each transmission attempt. A M/G/1 queuing model is
used in this work to analyze the queuing delay in 5G NR when there are multiple
uses in the system. Numerical results show that significant performance gains
and lower outage probability can be achieved by applying AFD.
