Joint Optimization Scheme for Transmission Powerand Pilot Allocation in TDD Massive MIMO Systems

Massive multiple-input multiple-output (MIMO) has been proposed as a key technology for the future cellular networks. In this paper, to reduce degradation of pilot contamination, we propose a joint optimization scheme for transmission power and pilot allocation in time division duplex massive MIMO systems. Based on the temporal channel correlation, Kalman filter is used to estimate channels. Considering the tradeoff of performance and complexity, the deterministic approximation of data rate in the first slot is derived as a function of the statistics values. To maximize the minimal rate of the system, transmission power and pilot allocation are iteratively optimized, where the pilot power and data power are derived using successive approximation and slack variables, and the pilot allocation is adjusted in the order of the ratio of channel gains and interferences. Simulation results confirm that the proposed scheme is effective to improve the minimal rate.