In this paper, we revisit the frequency allocation scheme (FAS) for the homogeneous cellular networks by taking the non-uniform distribution of users into account. Owing to the non-uniformly distributed user density from sector to sector, the traffic loads become highly unbalanced across whole network. Thus, to satisfy users' requests, the dynamic user-oriented FAS (Duo-FAS) is proposed to allocate different amount of subcarriers to sectors according to the variant user densities. However, the Duo-FAS technique can partially remove the innate benefit of interference avoidance via frequency planning, i.e. the conventional three-sectored cell architecture. That means some extra inter-cell interference (ICI) can be produced by using Duo- FAS. Fortunately, the network multiple-input and multiple-output (MIMO) technique can effectively alleviate the impact of ICI. Thanks to Duo-FAS, the number and positions of the cooperative cells when using the network MIMO technique can be significantly different from the conventional schemes. Thus, properly selecting the cooperative cells becomes a pivotal issue. The key is that for any particular user, the neighboring cells to form a cooperative network MIMO group should be adaptively selected so that the strong ICI can be eliminated. The simulation results demonstrated the higher achievable cell capacity.