What the result of a Graduated non-convexity function，as you can see,the problem is non convex when B is large ,but cvx still can give me the result,can i believe it

3

Other than the double summation, your problem formulation basically uses CVBX acceptable formulations provided to you in your previous question Channel optimal problems - #7 by Mark_L_Stone . So I don’t know why you thought this problem is not convex.