Novel Post-Weighting Digital Predistortion Structures for Hybrid Beamforming Systems

We propose a new method to tackle the predistortion problem for the hybrid beamforming structure of Millimeter-Wave (MM-Wave) Massive MIMO in 5G communication systems in order to widen the linearized angle of beams without any requirement or retuning on the nonlinearities of power amplifiers (PA). The new method adopts one common Digital Predistortion (DPD) block per subarray followed by a post-weighting block, and the predistorted signals are re-distributed to different subarrays to form a pattern to compensate for the distortions in different directions simultaneously. Two implementations with low complexity are introduced in this letter.