A quadratic-interpolated LUT-based digital predistortion technique for cellular power amplifiers
Journal
IEEE Transactions on Circuits and Systems II: Express Briefs
Journal Volume
61
Journal Issue
3
Pages
133-137
Date Issued
2014
Author(s)
Abstract
Baseband digital predistortion (DPD) is an efficient and low-cost method for linearizing a power amplifier (PA) in a wireless system using a modulation scheme with nonconstant envelope. The polynomial and the lookup table (LUT) predistortion schemes are two commonly used approaches. Both approaches require time to find the inverse characteristics of the PA to be predistorted. However, for DPD to be actually implemented in real-world scenarios, fast convergence is highly desirable. A low-complexity joint-polynomial/LUT predistortion PA linearizer is proposed to obtain fast linearization. The algorithm utilizes quadratic interpolation of the LUT, which reduces the required LUT size and hence reduces convergence time without degradation of linearity. Simulation result shows that the proposed method can achieve up to 500% improvement in convergence speed compared with the conventional linear interpolation approach for the wideband code-division multiple access application. © 2014 IEEE.
Subjects
Digital predistortion (DPD); Linearization; Lookup table (LUT); Power amplifier (PA)
Other Subjects
Code division multiple access; Interpolation; Inverse problems; Linearization; Table lookup; Baseband digital predistortion; Digital predistortion; Digital predistortion techniques; Inverse Characteristics; Linear Interpolation; Look up table; Quadratic interpolation; Wideband code division multiple access; Power amplifiers
Type
journal article