Accuracy-Enhanced IRS-Aided Target Sensing With RSS by Exploiting Path-Loss Fading

Mobile wireless sensing in communication networks has been well perceived as a technology tendency. By applying commercial communication infrastructures, advanced target (localization) sensing can be fulfilled. This is particularly feasible for 6G networks where the wireless nodes are evolving to be much denser, and new techniques such as intelligent reflecting surface (IRS) emerge. In this context, short distance sensing remains challenging because the high-accurate wide-band sensing may be degraded due to the factors of severe fading, non-line-of-sight links, etc. To address this problem, we propose a sensing method based on received-signal-strength via assistance of IRS. By elaborately designing the beamforming vectors and amplifying power of the IRS, we purposely increase the path-loss fading exponent and hence efficiently obtain more accurate sensing performance. Besides, the proposed placement to deploy base-stations (reference points) can minimize the average sensing error considering the user uniformly random in a circular region, where a closed-form low-bound for sensing error is provided as theoretical reference. The effectiveness of the proposed method is verified by numerical studies.