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Performance Analysis of Two-Tier HetNets With Massive MIMO and Nonuniformly Small Cell Deployment

The performance of a coordinated multipoint transmission for massive multiple-input multiple-output (MIMO) heterogeneous networks with practical deployment is investigated. The active small cell base stations outside the inner region of macrocell base stations are used to improve the performance of macrocell edge users. Based on the stochastic geometry approach, the spectral efficiency (SE) and energy efficiency (EE) of the proposed scheme are analyzed. An alternating optimal algorithm is employed to solve the EE maximization problem effectively. The impacts of the small cell density, inner region size, and massive MIMO on the network performance are explicitly examined. Moreover, by approximating the interference distribution by moment matching with the Gamma distribution, the coverage probability of the two-tier HetNet is also studied. Numerical results show that the proposed HetNet generally outperforms the conventional maximum receive power association scheme and it provides a potential solution to achieve high SE and EE performance.