Full-Duplex Wireless LAN Incorporating Successive Interference Cancellation

Abstract

Support for an asymmetric transmission topology involving two user stations, one for downlink and one for uplink, is essential in full-duplex wireless LANs to handle asymmetric and heterogeneous traffic demands as well as heterogeneous station capabilities. The main challenge presented by this asymmetric topology is interstation interference from the uplink-transmitting station to the downlink-receiving station. In this paper, we develop a novel medium access control (MAC) protocol and an associated station selection algorithm that exploit successive interference cancellation (SIC) to resolve the interstation interference. To understand the problem and find design rationales, we establish concepts of distinct transmission types and conduct a formal analysis of decodability with SIC, based on which we show that a transmission-type-specific design is necessary due to the type-dependent information requirements and asymmetric availability of information. We define, identify, and illustrate the SIC-eligible, interference and noninterference regions, each of which has different decodability characteristics. The developed MAC protocol is designed to guarantee coexistence with legacy wireless LANs. The developed station selection algorithm is designed to handle all possible transmission cases of full-duplex communication in both the centralized and distributed operation modes, which differ in terms of the signaling overhead and achieved performance; moreover, this algorithm can be combined with a wide range of access point schedulers. Through comprehensive simulation, we demonstrate that the proposed scheme considerably enhances the system and per-station throughputs compared with conventional schemes, approaching the ideal case with no interstation interference.