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The Journal of China Universities of Posts and Telecommunications 2012年第2期19卷 43-47页

作者： YU Cui-ping LIU Yuan-an DU Tian-jiao LI Shu-lan School of Electronic Engineering Beijing University of Posts and TelecommtmicationsBeijing 100876Chma

A triangular memory polynomial （TMP） predistorter is presented in this paper to linearize a power amplifier＇s nonlinear with memory effects. Compared with the traditional memory polynomial （MP） predistorter, the coefficients of TMP predistorter is reduced more than 75%, which can effectively decrease the implementation complexity. The coefficients of predistorter are directly extracted from an offline system identification process by an open-loop structure in our approach. Several signals with data rate 5 MHz, 10 MHz, 15 MHz and 20 MHz are used to verify the performance of the proposed predistorter. Experimental results show that the proposed TMP predistorter and the traditional MP predistorter almost have the same performance.

关键词： power amplifier predistortion memory effects memory polynomial

Step memory polynomial predistorter for power amplifiers with memory

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Journal of Southeast University(English Edition) 2009年第3期25卷 303-308页

作者：于翠屏刘元安黎淑兰南敬昌北京邮电大学电子工程学院北京100876 辽宁工程技术大学电子信息学院葫芦岛125105

To reduce the number of digital predistortion coefficients, a step memory polynomial （SMP）predistorter is presented. The number of predistortion coefficients is decreased by adjusting the maximum nonlinear order for different memory orders in the traditional memory polynomial （MP）predistorter. The proposed SNIP predistorter is identified by an offline learning structure on which the coefficients can be extracted directly from the sampled input and output of a PA. Simulation results show that the SMP predistorter is not tied to a particular PA model and is, therefore, robust. The effectiveness of the SMP predistorter is demonstrated by simulations and experiments on an MP model, a parallel Wiener model, a Wiener-Hammerstein model, a sparsedelay memory polynomial model and a real PA which is fabricated based on the Freescale LDMOSFET MRF21030. Compared with the traditional MP predistorter, the SMP predistorter can reduce the number of coefficients by 60%.

关键词： power amplifier predistortion memory effects memory polynomial

Robust power amplifier predistorter by using memory polynomials

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Journal of Systems Engineering and Electronics 2009年第4期20卷 700-705页

作者： Li Bo Ge Jianhua Ai Bo State Key Lab. of Integrated Service Networks Xidian Univ. Xi'an 710071 P. R. China School of Information Engineering Chang'an Univ. Xi'an 710064 P. R. China Engineering Coll. of Armed Police Force Xi'an 710086 P. R. China

In memory polynomial predistorter design, the coefficient estimation algorithm based on normalized least mean square is sensitive to initialization parameters. A predistorter based on generalized normalized gradient descent algorithm is proposed. The merit of the GNGD algorithm is that its learning rate provides compensation for the independent assumptions in the derivation of NLMS, thus its stability is improved. Computer simulation shows that the proposed predistorter is very robust. It can overcome the sensitivity of initialization parameters and get a better linearization performance.

关键词： power amplifier predistortion memory polynomial generalized normalized gradient descent orthogonal frequency division multiplexing.

Adaptive Digital Predistortion Schemes to Linearize RF Power Amplifiers with memory Effects

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Journal of Beijing Institute of Technology 2008年第2期17卷 217-221页

作者：张鹏吴嗣亮张钦 School of Information Science and Technology Beijing Institute of Technology

To compensate for nonlinear distortion introduced by RF power amplifiers （PAs） with memory effects, two correlated models, namely an extended memory polynomial （EMP） model and a memory lookup table （LUT） model, are proposed for predistorter design. Two adaptive digital predistortion （ADPD） schemes with indirect learning architecture are presented. One adopts the EMP model and the recursive least square （RLS） algorithm, and the other utilizes the memory LUT model and the least mean square （LMS） algorithm. Simulation results demonstrate that the EMP-based ADPD yields the best linearization performance in terms of suppressing spectral regrowth. It is also shown that the ADPD based on memory LUT makes optimum tradeoff between performance and computational complexity.

关键词： adaptive digital predistortion power amplifiers memory polynomial lookup table wideband code division multiple access (WCDMA)

DYNAMIC BEHAVIORAL MODELING FOR STRONGLY NONLINEAR DOHERTY PAS USING REAL-VALUED TIME-DELAY RECURRENT RBF MODEL

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Journal of Electronics(China) 2012年第1期29卷 39-45页

作者： Hui Ming Liu Taijun Ye Yan Zhang Haili Shen Dongya Li Liang Department of Information Scienc eand Engineering Ningbo UniversityNingbo 315211China Zhejiang College of Textile&Fashion Ningbo 315211China Department of Information Science and Engineering Yunnan UniversityKunming 650091China

This paper proposes a Real-Valued Time-Delay Recurrent Radial Basis Function (RVTDRRBF) model suitable for dynamic modeling of the strongly nonlinear behaviors of the Doherty Power Amplifiers (DPAs). This model has four Tapped Delay Lines (TDLs), which account for the memory effect of the DPA. The structure of the RVTDRRBF model is simpler than the traditional FeedForward Neural Networks (FFNNs) model. Weights and centers of the proposed model can be resolved by the Orthogonal Least Square (OLS) and Singular Value De-composition (SVD) algorithm. A three-carrier Wideband Code Division Multiple Access (WCDMA) signal is taken as the test signal. The simulation results in frequency-domain and time-domain for a DPA with 51 dBm output illustrate a good agreement between the RVTDRRBF model and measurement data. Moreover, comparing the Normalized Mean Square Error (NMSE) of RVTDRRBF model, memory polynomial model and RVTDRBF model, it can be noticed that the proposed RVTDRRBF model is more accurate than the RVTDRBF model and the memory polynomial model in modeling the strong dynamic nonlinearity of the DPAs.

关键词： Radial Basis Function (RBF) Power Amplifiers (PAs) memory polynomial Doherty

DYNAMIC BEHAVIORAL MODELING FOR STRONGLY NONLINEAR DOHERTY PAS USING REAL-VALUED TIME-DELAY RECURRENT RBF MODEL

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Journal of Electronics(China) 2012年第Z1期 39-45页

作者： Hui Ming Liu Taijun Ye Yan Zhang Haili* Shen Dongya** Li Liang (Department of Information Science and Engineering, Ningbo University, Ningbo 315211, China) *(Zhejiang College of Textile & Fashion, Ningbo 315211, China) **(Department of Information Science and Engineering, Yunnan University, Kunming 650091, China)

关键词： Radial Basis Function (RBF) Power Amplifiers (PAs) memory polynomial Doherty