Overview: 

OFDMA random access has been proposed to support multi-user (MU) transmission in 802.11ax. In the OFDMA random access, the stations randomly select sub-channels to send their frames without coordination. As a result, the channel utilization is less than 37%. To this issue, a new OFDMA random access scheme is proposed to improve the channel utilization. The proposed scheme is theoretically analyzed, and simulated in several scenarios. The evaluation results demonstrate that the proposed scheme dramatically improves the efficiency of the UORA. 

People: Dianhan Xie, Jiawei Zhang, Aimin Tang