A Submodular Optimization Framework for Outage-Aware Cell Association in Heterogeneous Cellular Networks

Figure 1

A visual illustration of user associations under different association scheme. The simulated HetNet consists of 1 macro-BS, 10 SBSs, and 100 users. The outage threshold is 0 dB. The dark solid lines denote associations with the macro-BS and green dashed lines denote associations with SBSs.

(a) Max SINR scheme

(b) Log utility maximization

(c) Log utility maximization with weighted loads