An adaptive pre-distorter for the compensation of HPA nonlinearity

Author

Han, Dong-Seog ; Hwang, Taewon

Author_Institution

Sch. of Electron. & Electr. Eng., Kyungpook Nat. Univ., Taegu, South Korea

Volume

46

Issue

2

fYear

2000

fDate

6/1/2000 12:00:00 AM

Firstpage

152

Lastpage

157

Abstract

A high power amplifier (HPA) is used for the amplification of transmitting communication signals. However, it produces distortions by creating AM/AM and AM/PM modulations in the transmitting signal, Accordingly, this nonlinearity results in bandwidth expansion and nonlinear distortion in the in-band signal. This paper proposes an algorithm for the operation of a pre-distorter, which is composed of a look-up table (LUT), that can compensate for the distortion produced by an HPA. For the fast initialization of the LUT, an estimation algorithm is also proposed for the HPA characteristics. Furthermore, an adaptive algorithm based on the minimization of the mean square error is proposed to compensate for the time-varying property of an HPA. The performance of the proposed algorithm is analyzed by applying the algorithm to an 8-level vestigial sideband (VSB) modulation to be used in the ATSC terrestrial digital TV system

Keywords

adaptive estimation; compensation; digital television; least mean squares methods; nonlinear distortion; power amplifiers; radiofrequency amplifiers; table lookup; television transmitters; 8-level vestigial sideband modulation; AM/AM modulation; AM/PM modulation; ATSC terrestrial digital TV system; HPA nonlinearity; VSB; adaptive pre-distorter; amplification; bandwidth expansion; compensation; distortions; high power amplifier; in-band signal; initialization; look-up table; mean square error minimization; nonlinear distortion; performance; time-varying property; Adaptive algorithm; Algorithm design and analysis; Bandwidth; Digital modulation; High power amplifiers; Mean square error methods; Minimization methods; Nonlinear distortion; Performance analysis; Table lookup;

fLanguage

English

Journal_Title

Broadcasting, IEEE Transactions on

Publisher

ieee

ISSN

0018-9316

Type

jour

DOI

10.1109/11.868931

Filename

868931