A Low-Complexity Post-Weighting Predistorter in a mMIMO Transmitter Under Crosstalk

In hybrid beamforming, the beam oriented digital predistortion (BO-DPD) is incompetent to linearize the output in different directions except the desired direction to the transmitter. Therefore, subsequent to the BO-DPD operation, we perform a post-weighting (PW) processing to minimize the nonlinear radiations in the wide range of directions. Here, the optimized PW coefficients are multiplied by the polynomial basis functions of the BO-DPD, then, the resultant signals are distributed to the PAs to compensate the nonlinear radiations. In this work, first, we propose fully-featured post-weighting (FF-PW) scheme, then, we derive a low-complexity post-weighting (LC-PW) scheme.