A. The Best-Near Best-Far (BNBF) User Selection SchemeThe proposed user selection process is conducted beforedata transmission through the signaling and channel stateinformation estimation/calculation system. Specifically, a nearuser Ns ∈ N and a far user Fs ∈ F that have thebest respective channel conditions will be selected in eachtransmission slot. Mathematically, the BNBF selection criterion can be described as Ns = arg maxi=1,...,N |hSNi |2,Fs = arg max j=1,...,M |hSF j |2.