A Dual-Input Canonical Piecewise-Linear Function-Based Model for Digital Predistortion of Multi-Antenna Transmitters
In this paper, a novel dual-input canonical piecewise-linear (CPWL) function-based behavior model is proposed for the digital predistortion of multi-antenna transmitters with antenna mutual coupling. The proposed model can be applied to each path separately. By employing CPWL technique, the proposed model can handle higher-order nonlinearity of antenna crosstalk easily, and is more flexible and precise to model power amplifiers. The dynamic deviation reduction conception is used to further optimize the terms of the proposed dual-input model, which avoids the quick increase of the coefficient number when requiring longer memory depth and higher-order nonlinearity. An experiment with two-antenna transmitters is designed to validate the proposed model. The excellent experiment results indicate that the proposed behavior model has a better performance in DPD of multi-antenna transmitters, compared to conventional Volterra-based models.