Abstract: For the orbital angular momentum (OAM) combined with multiple input multiple output (MIMO) system based on uniform circular array (UCA), the design of UCA affects the channel gain and the system performance. In order to further study the impact of the UCA design on the energy efficiency of OAM-MIMO system, the UCA radius, the number of antennas of UCA and transmission power are jointly optimized to maximize the energy efficiency, while improving the communication quality of each channel. Due to the coupling of several optimization variables, the considered optimization problem is non-convex and difficult to be solved directly. Therefore, an optimization algorithm combining genetic algorithm and particle swarm optimization with convex optimization method is proposed. Simulation results show that the proposed resource optimization algorithm is closed to the exhaustive algorithm combined with convex optimization, which can effectively improve the system energy efficiency.

Key words: orbital angular momentum ,  multiple input multiple output , energy efficiency, capacity, resource optimization