SWAN: Stitched Wi-Fi ANtennas.

This paper presents our experience in designing, implementing, testing, and applying a general-purpose antenna extension solution with commodity Wi-Fi. The proposed solution, SWAN, builds an array of stitched antennas extended from the radio chains of commodity Wi-Fi. SWAN has low hardware cost and provides easy-to-use interfaces embedded in the Linux kernel. Two application cases for wireless sensing and communication are presented that proves the usefulness of the solution. SWAN is able to provide over 3× performance improvement on Wi-Fi azimuth estimation and localization and over 30% improvement on Wi-Fi throughput over original Wi-Fi AP with three fixed antennas.