“…With advancements in wireless communication technology, sixth generation (6G) is bringing advanced technologies, such as mm-Wave [ 1 , 2 , 3 ], unmanned aerial vehicles (UAVs) [ 4 , 5 , 6 ], tera-hertz (THz) communications [ 7 , 8 , 9 ], intelligent reflecting surfaces (IRS) [ 10 , 11 , 12 ], non-orthogonal multiple access (NOMA) [ 13 , 14 , 15 ], etc., to overcome the limitations of prior wireless generations. Indoor positioning systems (IPSs) and location-based services have become a fundamental requirement for many Industrial Internet of Things (IIoT) applications [ 16 , 17 , 18 ].…”