A Modified Power Control Algorithm for Coordinating CLI in Massive MIMO System

In the fifth generation (5G) mobile communication system, massive multiple input multiple output (MIMO) and dynamic time division duplex (TDD) are key technologies which can greatly improve system performance. However, they may cause severe inter-cell cross-link interference (CLI). In allusion to the problem mentioned above, this paper presents a modified power control (MPC) algorithm which has low complexity and high flexibility for above issue. The purpose of MPC is to coordinate the CLI by dynamically adjusting the step size of power control so that the transmit power can quickly converge to the target value. And the adjustment process is first quick back slow so that transmit power decreasing rapidly in early stage can make the coordination effect on CLI more obvious. Besides, the algorithm also sets a margin to eliminate the problems that the adjustment process is endless and the power oscillates around the target. Through the simulations, it is verified that MPC can improve effectively system performances which improve SINR around 3dB and doubles the speed of adjustment process compared with other algorithms involved in simulations.