Joint User Association, Power Allocation, and Throughput Maximization in 5G H-CRAN Networks

In order to get worthwhile gain in coverage and capacity required by fifth generation networks, dense heterogeneous networks are being considered as promising solution. Heterogeneous networks consists of small cells overlaid on macrocells. Introduction of small cells within the coverage of macrocell give birth to problems such as user association, power allocation, and admission control. To address these problems and to maximize overall network throughput heterogeneous networks are integrated with cloud radio access network (CRAN). We formulated a joint user association, admission control, and power allocation problem in heterogeneous CRAN with an objective to maximize overall throughput of network. By examining the structure of the problem, we categorize it under mixed integers nonlinear problems that are generally NP-hard. This paper presents an outer approximation approach (OAA) based on linear programming that simplifies the NP-hard problem, which requires an exhaustive search. OAA ensures <inline-formula><tex-math notation="LaTeX">$\varepsilon$</tex-math></inline-formula>-optimal solution with <inline-formula><tex-math notation="LaTeX">$\varepsilon =10^{-3}$</tex-math></inline-formula>. OAA converges in a finite number of computations. Effectiveness of proposed algorithm is verified by simulation results.