Fifth-Generation Control Channel Design: Achieving Ultrareliable Low-Latency Communications

Abstract

This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. 2 ||| 1556-6072/18©2018ieee ieee vehicular technology magazine | June 2018 This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination.

Control channel enhancements for ultra-reliable low-latency communications

“…In this case, the BLER of decoding the message is reduced to 2 . The success probability of delivering a message can be expressed as [4] = Figure 3(b) illustrates the reliability requirements for the control information to achieve the reliability of 1 − 10 −5 in downlink. The initial transmission round is performed with three different reliability targets.…”

“…For instance, the gNB would select more robust MCS for the transmission if the time budget is low, due to the buffer latency or missing the previous SR by the gNB. It is shown that the inclusion of such information can also relax the reliability constraint on the SR [4]. …”

“…To solve this issue, the ACK/NACK repetition can be performed during a single TTI while utilizing different frequency resources.  Asymmetric ACK/NACK signal detection: As mentioned, protecting the NACK signal is more important than protecting the ACK signal, as erroneous NACK detection degrades the communication reliability [4], [7]. This brings forward the idea of using enhanced NACK protection by applying an asymmetric signal detection.…”

“…This paves the way for fundamental changes to the NR, which can bring better support for URLLC. While these two paths lead to different network designs, they might benefit from similar techniques for integrating URLLC [4]. However, URLLC can only be implemented if the highreliability and low-latency features are addressed in the whole system [5].…”

“…These channels exhibit different impacts on the overall communication performance. Thus, different reliability and latency constraints are imposed to the channels according to the given communication service [4]. Since these constraints are usually stringent for URLLC, new approaches and designs are needed for the data and control channels.…”