The Research On The Low Complexity Digital Predistortion Models For Concurrent Multi-band Signals

With the rapid development of modern wireless communication technology,several communication patterns,such as 2G,3G and 4G,coexist in communication systems.Meanwhile,several novel technologies,such as carrier aggregation,are applied widely,which lead the concurrent multi-band/wideband power amplifier and its linearization methods becoming the hot topic.This thesis focuses on the research of multi-band signals' digital predistortion.The main work and innovation points are as follow:1.Proposed a Dual-band Nonuniform Low Complexity Memory Polynomial model.This model describes the in-band intermodulation,the cross-band modutation,the static nonlinearity and the dynamic nonlinearity separately.Based on the distinction of these components,the nonlinear orders and memory depths are set differently to decrease the number of coefficients.The test results verified that compared to DB-MP model,the DB-LCMP model and the DB-SDDR model,the predistortion performance is at the same level,but the complexity is only 22%,27%and 70%.Compared to DB-MMP model,the complexity is at the same level,however the NMSEs of both band are 3dB better than DB-MMP model,and the ACPRs of both band are 1dB better than DB-MMP model.The results could verified the advantage of the proposed model.2.Proposed a Dual-Up-Conversion Tri-band digital predistortion architecture,and the tri-band joint predistortion model of both I/Q imbalance and PA nonlinearity(TB-DJMP),which is suitable for DUC architecture.The test results show that when considering the instruments'I/Q imbalance,the TB-DJMP model's NMSEs are 12dB better than TB-MP's,and the ACPRs are 13dB better than TB-MP's.