• Citer

Impact of MU-MIMO on passive Wi-Fi radars: threat or opportunity?

par Yildirim, Hasan Can ;Storrer, Laurent ;Louveaux, Jérôme;De Doncker, Philippe ;Horlin, François
Référence (09-10 March, 2022: Seefeld, Austria), Proc. of the 2nd IEEE International Hybrid Symposium on Joint Communications & Sensing (JC&S22)
Publication Publié, 2022-03

Publication dans des actes

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Passive Radars are devices that make use of existingcommunication signals for wireless channel sensing. On the otherhand, Wi-Fi has become the main gateway that connects devicesto the internet. Recently, IEEE established the WLAN SensingTask Group whose purpose is to study the feasibility of Wi-Fi-based environment sensing, where some of the technologiesshare similarities with Passive Radars. In the meantime, Multi-User Multiple-Input Multiple-Output (MU-MIMO) technologyis introduced to the Wi-Fi standard. It is designed to improvethe spatial efficiency of the wireless channel by simultaneouslytransmitting directive Wi-Fi signals to users. This paper aimsat quantifying the impact of MU-MIMO signals on Passive Wi-Fi-based Radar-like sensing. First, based on the position of theclient devices and the channel geometry, the radiation pattern ofthe AP is derived. While the wireless channel is illuminated bydirective radio waves, the magnitude of the Poynting vector isobtained at a local point target, which then reflects the incidentradio waves. Finally, the signal power seen by a sensing deviceis computed under the influence of a multipath channel. Ournumerical analyses focus on an urban street, and we show thatMU-MIMO can be seen as; i) an opportunity, since the vicinityof client devices are better illuminated, or ii) a threat, since theremaining parts of the street do not receive sufficient amount ofpower for channel sensing applications.