An Improved Digital Predistortion Structure with Dynamic Tuning for 5G Transmitters

In this paper, an improved digital predistortion (DPD) module technique with real power amplifiers (PAs) dynamic tuning is proposed to linearize the massive multiple-input-multiple output (mMIMO) system. The PA characteristics on each transmitting chain are detected firstly, and then the subarrays are linearized dynamically with a tuning box. This method linearizes the power amplifier in the case of lower computational complexity and ensures excellent performance. To evaluate the performance of the proposed method, an mmWave beamforming transmitter was used for testing and excitation with a single carrier 30-MHz and a tri-carrier 30-MHz long term evolution (LTE) with the center frequency is 3.6GHz and 2.65GHz respectively. The measured results demonstrate that the proposed method has lower computational complexity and can achieve better adjacent channel power ratio (ACPR) performance.