采用辅助转动装置的MIMO系统双目标DPD实验研究

Experimental Research on Two-Target DPD in MIMO System Using Auxiliary Rotation Device

文中介绍了一种双目标数字预失真(DPD)方案,并进行了实验研究。不增加系统复杂度的情况下,可以有效地扩展MIMO系统的线性化波束宽度。在发射机附近增设一个发射低功率信号的线性辅助转动装置,该架构实现了MIMO系统主波束线性化。实验平台由发射机系统和一个辅助转动装置组成,发射机天线阵列为1×4。输入信号采用两个20 MHz带宽峰均比分别为5.7 dB和5.6 dB的正交频分复用(OFDM)信号。实验研究结果表明,采用了辅助转动装置的双目标DPD方法后,邻信道功率比(ACPR)达到-50 dBc以下的主波束线性化宽度可以扩展到22°,同时信号归一化均方误差(NMSE)平均数值为-40 dB。该方案有效地拓宽了MIMO系统线性化波束宽度。

This paper introduces a two-target digital predistortion (DPD) architecture and conducts experimental studies.The two-target DPD architecture can effectively extend the linearized beamwidth of multiple input multiple output (MIMO) systems without increasing system complexity.The proposed architecture adds an auxiliary small antenna array near the transmitter and emits low-power signals to achieve linearization of the system beam.The experimental platform is composed of a four-antenna beamforming transmitter system and a two-antenna auxiliary array.The input signal is an orthogonal frequency division multiplexing (OFDM) signal with a bandwidth of 20 MHz and a peak power of 5.7 dB/5.6 dB.Experimental results show that the linearized width of the main beam can reach 22°(adjacent channel power ration (ACPR) is below -50 dBc),the average NMSE in this angle range is -40 dB.The proposed two-target DPD method can effectively widen the beam linearization width of the MIMO transmitter system.