A method for synchronized selection of user equipments, UEs, for both downlink, DL, Multi-User Multiple Input Multiple Output, MU-MIMO, operation and uplink, UL, MU-MIMO operation in a wireless cell, comprising: applying, by one of an Evolved Node B (eNB) or a Next Generation Node B (gNB), a common set of selection criteria for selecting a common pool of UE candidates to implement MU-MIMO-allocation user pairing for both DL MU-MIMO operation and UL MU-MIMO operation, wherein the common set of selection criteria are applied in Stage-1 selection process to select Stage-1 candidates for a UE candidates list; and if the Stage-1 selection process applying the common set of selection criteria is not able to find UE candidates to fill available slots in the UE candidates list, initiating, by one of the eNB or the gNB, Stage-2 selection process involving 1) applying a first set of Stage-2 selection criteria to select DL-only traffic UEs as Stage-2 candidates for the UE candidates list, and 2) applying a second set of Stage-2 selection criteria to select UL-only traffic UEs as Stage-2 candidates for the UE candidates list, wherein: the number of the Stage-1 candidates is represented by M1N1; the number of Stage-2 DL-only traffic candidate UE is represented by M; the number of Stage-2 UL-only traffic candidate UE is represented by N; Sounding Reference Signal, SRS, capacity of the wireless cell is represented by n; and at least one of i) M1N1 + M = n, ii) M1N1 + N = n, iii) M1N1 + M = n/2, and iv) M1N1 + N = n/2. applying, by one of an Evolved Node B (eNB) or a Next Generation Node B (gNB), a common set of selection criteria for selecting a common pool of UE candidates to implement MU-MIMO-allocation user pairing for both DL MU-MIMO operation and UL MU-MIMO operation, wherein the common set of selection criteria are applied in Stage-1 selection process to select Stage-1 candidates for a UE candidates list; and if the Stage-1 selection process applying the common set of selection criteria is not able to find UE candidates to fill available slots in the UE candidates list, initiating, by one of the eNB or the gNB, Stage-2 selection process involving 1) applying a first set of Stage-2 selection criteria to select DL-only traffic UEs as Stage-2 candidates for the UE candidates list, and 2) applying a second set of Stage-2 selection criteria to select UL-only traffic UEs as Stage-2 candidates for the UE candidates list, wherein: the number of the Stage-1 candidates is represented by M1N1; the number of Stage-2 DL-only traffic candidate UE is represented by M; the number of Stage-2 UL-only traffic candidate UE is represented by N; Sounding Reference Signal, SRS, capacity of the wireless cell is represented by n; and at least one of i) M1N1 + M = n, ii) M1N1 + N = n, iii) M1N1 + M = n/2, and iv) M1N1 + N = n/2. the number of the Stage-1 candidates is represented by M1N1; the number of Stage-2 DL-only traffic candidate UE is represented by M; the number of Stage-2 UL-only traffic candidate UE is represented by N; Sounding Reference Signal, SRS, capacity of the wireless cell is represented by n; and at least one of i) M1N1 + M = n, ii) M1N1 + N = n, iii) M1N1 + M = n/2, and iv) M1N1 + N = n/2.