A Discrete Newton's Method for Gain Based Predistorter
- 1 School of Electronic and Information Engineering Dalian University of Technology, Dalian, P.R.China
- 2 School of Electronic and Information Engineering Dalian University of Technology, Dalian, P.R.China
- 3 School of Electronic and Information Engineering Dalian University of Technology, Dalian, P.R.China
Abstract
Gain based predistorter (PD) is a highly effective and simple digital baseband predistorter which compensates for the nonlinear distortion of PAs. Lookup table (LUT) is the core of the gain based PD. This paper presents a discrete Newton’s method based adaptive technique to modify LUT. We simplify and convert the hardship of adaptive updating LUT to the roots finding problem for a system of two element real equations on athematics. And we deduce discrete Newton’s method based adaptive iterative formula used for updating LUT. The iterative formula of the proposed method is in real number field, but secant method previously published is in complex number field. So the proposed method reduces the number of real multiplications and is implemented with ease by hardware. Furthermore, computer simulation results verify gain based PD using discrete Newton’s method could rectify nonlinear distortion and improve system performance. Also, the simulation results reveal the proposed method reaches to the stable statement in fewer iteration times and less runtime than secant method.
- J. K. Cavers, “Amplifier Linearization Using a Digital Predistorter with Fast Adaptation and Low Memory Requirements”, IEEE Trans. Veh. Technol.,Vol. 19, No. 4, Nov. 1990, pp. 374-382
- Won Gi Jeon, Kyung Hi Chang, and Yong Soo Cho,"An Adaptive Data Predistorter of Compensation of Nonlinear Distortion in OFDM System", IEEE Trans. Commun., Vol. 45, No. 10, Oct. 1997, pp.1167-1171.
- Minglu Jin, Sooyoung Kim, Doseob Ahn, Deock-GilOh, and Jae Moung Kim, "A Fast LUT Predistorter for Power Amplifier in OFDM Systems", The 14th IEEE Intemational Sysmposium on personal Indoor and Mobile Radio Communication Proceedings , Beijing, China, Sep. 2003, pp. 1894-1897
- Hongxin Zhao, Yiyuan Chen, and Wei Hong, "A Baseband Predistortin Linearizer for RF power amplifier Prototype Simulation and Experimentation", Journal of China Insttiute of Communications, Vol. 21, No. 5, May. 2000, pp.41-47.
- Shuyue Wu, Xinguang Tian, and Ping Bao, "A Fast Algorithm of the Linearizing Technology of the Adaptive Power Amplifiers", Signal Processnig, Vol.18, No.3, Jun.2002, pp. 254-256.
- Shuyue Wu, Wenming Guo, Xin Song, and Xinguang Tian, “A New Algorithm of the Linearizing Technology of the Digital Baseband Predistortion”, J. Xiangtan Min. Inst., Vol. 19, No. 1, Mar. 2004, pp. 63-65.
- Kathleen J. Muhonen, and Mohsen Kavehrad, “Look-Up Table Techniques for Adaptive Digital Predistortion: A Development and Comparison”, IEEE Trans. Veh. Technol., Vol. 49, No. 5, Sep.2000, pp.1995-2000.
- Chih-Hung Lin, Hsin-Hung Chen, Yung-Yi Wang, and Jiunn-Tsair Chen, “Dynamically Optimum Lookup-Table Spacing for Power Amplifier Predistortion Linearization”, IEEE Trans. Micro. Theory Tech., Vol. 54, No. 5, May.2006, pp. 2118 -2127.
- Rubiao Xie, and Peiqing Jiang, Nonlinear Numerical Analysis, Press of Shanghai Jiaotong University, Shanghai, China, 1984.
- A. A. M. Saleh, “Frequency-independent and frequency-dependent nonlinear models of TWT amplifiers”, IEEE Trans. Commun., Vol. COM-29, Nov. 1981, pp. 1715-1720.