Linear precoding based on nonlinear high‐power amplifier in massive MIMO

Summary Massive multi-input multi-output has the advantages of high energy efficiency and spectrum use, but it also brings some problems because of cheap hardware use, such as high-power amplifier (HPA) nonlinearity. When the HPA operates in the nonlinear regime, nonlinear distortions, including amplitude and phase distortions, are introduced into the transmitted symbols, which in turn can cause adjacent channel interference and power losses. In this paper, we first study the deficiency of the conventional precoding algorithm when the HPA is nonlinear. Then, this paper proposes the improved precoding algorithms according to the effect of HPA nonlinearity on the signal, in which the adaptive factor is achieved to largely control the amplitude and phase distortions of the nonlinear HPA. Finally, the simulation results are provided and show that the proposed algorithms in this paper based on the relative block of diagonalization precoding and the forced zero precoding can efficiently decrease the bit error rate and increase the throughput, especially in the case of high signal-to-noise ratio.