Resource Allocation in Switched-Beam Based mmWave MIMO CRAN

This paper focuses on the joint beam, subcarrier and power allocation in switched-beam based massive multiple-input-multiple-output (MIMO) orthogonal frequency division multiple access (OFDMA) system working at the millimeter wave (mmWave) frequency band, with the target of maximizing the weighted sum rate. The idea of cloud radio access network (CRAN) is also introduced into the system. To solve the optimization problem, we first divide it into two subproblems: 1) beam allocation for fixed subcarrier and power allocation; 2) subcarrier and power allocation for fixed beam allocation. For the first subproblem, a heuristic beam allocation algorithm is proposed. For the second subproblem, we transform it into a convex problem and solve it by using the proposed optimization algorithm based on the difference of two convex functions approximation (DCA) method. A low-complexity algorithm is also proposed to further reduce the complexity. Simulation results demonstrate that the proposed algorithms can enhance the weighted sum rate of the wireless transmission system significantly.