Collision decoding and reporting: A new collision resolution approach using full-duplex radio in WLANs

Full-duplex radio is a next-generation wireless communication technology, because it allows signals to be sent and received simultaneously within the same channel by cancelling self-interference signals. Thus, many full-duplex medium access control (MAC) protocols have been proposed to utilize the full-duplex radio. For backward compatibility with legacy stations (STAs), most of them operate based on the IEEE 802.11 distributed coordination function, which is a competition-based distributed method. Consequently, collisions among STAs are still an important problem in designing a full-duplex MAC protocol. Unlike traditional half-duplex radio, full-duplex radio can sense incoming signals during transmission. Therefore, a novel collision resolution method suitable for the full-duplex radio is required. In this paper, we propose a new collision resolution method called collision decoding and reporting (CDR). In this method, if a collision is detected, each transmitter STA tries to decode another transmitter STA's frame by cancelling self-interference signals, and memorizes a decoded transmission information. Afterwards, it reports the decoded transmission information to access point (AP) by using its data frame. As a result, the AP knows that another transmitter STA has data to transmit, and offers a transmission opportunity to another transmitter STA without competition. Therefore, the throughput of wireless local area networks increases by reducing competition overheads such as idle back-off slots and collisions. To evaluate the performance of the CDR method, analytical evaluations and simulations have been performed. We observed that the proposed method achieves a throughput gain compared to existing collision resolution methods. (C) 2020 Elsevier B.V. All rights reserved.