In a hybrid beamforming, a single digital predistortion (DPD) is inefficient to address all the nonlinearities over a subarray of power amplifiers (PAs) with underlying crosstalk in a massive multiple-input multiple-output (mMIMO) transmitter. In this context, the proposed work describes a novel hybrid post-weighting (PW) scheme. Here, it extends the competence of one trained DPD to all PAs exclusively via following PW block associated with optimal coefficients along the basis functions of the DPD. Consequently, it reduces the nonlinear radiation significantly in a wide range of azimuth directions to the transmitter.

翻译：在混合波束赋形中，单个数字预失真（DPD）无法有效解决大规模多输入多输出（mMIMO）发射机中，子阵列内存在串扰的功率放大器（PA）群所引起的全部非线性问题。针对此场景，本文提出了一种新型混合后加权（PW）方案。该方案通过为DPD基函数配置最优系数的后加权模块，将单个已训练DPD的补偿能力扩展至所有PA。由此，在发射机较宽的方位角范围内，非线性辐射得到显著抑制。