RIS aided localization scenario, where  K unknown UEs communicate with BS by exploiting a set of N RISs deployed inside the monitoring area of size 10×10 meters. The direct LoS path between BS and UEs is blocked by an obstacle (orange block). Blue and red solid lines refer to the LoS paths connecting the k-th UE to the n-th RISs and the n-th RIS to the BS, respectively.