Table 1 The proposed scheme based on the degradation

1:

Get :β _{i j k} , j=1,2,…,L,k=1,2,…,K,U,Φ;

2:

While N _U ≠0 do

3:

For k=1:N _U

4:

Calculate ϕ^opt(U _k ) according to (18)

5:

Calculate ϕ^sub(U _k ) according to (19)

6:

Calculate d(U _k ) according to (20)

7:

End for

8:

Calculate U_sens according to (21)

9:

Assign the optional pilot sequence ϕ^opt(U_sens) to the user U_sens

10:

U←U∖U_sens

11:

Φ←Φ∖ϕ^opt(U_sens)

12:

N _U ←N _U −1

13:

N _Φ ←N _Φ −1

14:

End while