A Novel Digital Predistortion Based on Flexible Characteristic Detection for 5G Massive MIMO Transmitters

In this letter, a novel digital predistortion (DPD) technique based on characteristic detection of power amplifiers (PAs) and flexible tuning box is proposed for linearizing large-scale multiple-input-multiple-output (MIMO) system. In this new method, before linearizing the digital block subarray, the PA characteristics of each transmitting chain are detected first. In this way, all PAs can be linearized dynamically without wasting computation, and the performance can be guaranteed. Experiments are carried out to verify the effectiveness of the structure, an mmWave beamforming transmitter was used for measurement and excitation with two long-term evolution (LTE) input signals of single-carrier 30 MHz and four-carrier 20 MHz. The experimental results show that the proposed technique has lower computational complexity and can achieve excellent linearization performance.