Our paper has been accepted to IEEE Access

게시일: Dec 07, 2020 4:9:41 AM

Jihoon Kim's work titled "Uplink Channel Access Enhancement for Cellular Communication in Unlicensed Spectrum" with Jaehong Yi and Saewoong Bahk has been accepted to IEEE Access on December.

Congratulations!

Uplink Channel Access Enhancement for Cellular Communication in Unlicensed Spectrum

Jihoon Kim, Jaehong Yi, and Saewoong Bahk

Abstract

3GPP cellular communications in unlicensed spectrum allow transmission only after completing listen-before-talk (LBT) operation. For downlink, the LBT operation helps cellular traffic to coexist well with Wi-Fi traffic. However, cellular uplink transmission is attempted only at the time specifically determined by the base station after having a successful LBT and the user equipment (UE) may suffer transmission failure and delayed transmission due to Wi-Fi interference. As a result, cellular uplink traffic does not coexist well with Wi-Fi traffic. This paper mathematically analyzes the problem of unfairness between cellular and Wi-Fi for uplink channel access. To address the coexistence problem in unlicensed spectrum, we propose a standard-compliant approach, termed UpChance, which allows the UE to use a minimum length of uplink reservation signal and the base station to determine the optimal timing for the UE’s uplink transmission. Through ns-3 simulation, we verify that UpChance improves the performance of fairness and random access completion time by up to 88% and 99%, respectively.