Publication Journal: IEEE Transactions on Circuits and Systems-I: Regular Papers

Title: On the Robustness of Look-Up Table Digital Predistortion in the Presence of Loop Delay Error

Authors: You-Jiang Liu, Bin Lu, Tao Cao, Bang-Hua Zhou, Jie Zhou, and Yi-Nong Liu

Author Affiliations:  1. Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, China;    2.Department of Engineering Physics, Tsinghua University, Beijing 100084, China.

Status: Published in Vol. 59 Issue 10, 2012

Pages: 2432-2442

Abstract:  Look-up table (LUT) predistortion is the most promising technique to linearize RF power amplifiers (PAs). Before it can be employed successfully, loop delay errors must be estimated and compensated accurately. In this paper, the effect of loop delay errors on LUT predistortion is analyzed. It is shown that LUTs fluctuations happen to both amplitude and phase tables. Then, a novel loop delay estimation algorithm, with a high degree of robustness and accuracy, is presented. To further improve the robustness of LUT predistortion to loop delay errors, the smoothing filter (SMF) method to polish LUTs fluctuations is proposed here. LUT predistortion can suffer bigger loop delay errors because of the proposed SMF method, but retains good linearization performance close to the optimal one. The performance of the proposed loop delay estimation algorithm is investigated by comparative study with a state-of-the-art algorithm. Its robustness is also demonstrated under a noisy feedback path by simulations. The effectiveness of the SMF method is assessed by both simulations and experiments. Comparison among different predistortion systems is also presented. The results clearly show that the proposed techniques are useful for LUT predistortion.

Email: liuyj04@163.com

URL: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6148314&contentType=Journals+%26+Magazines&queryText%3DOn+the+Robustness+of+Look-Up+Table+Digital+Predistortion+in+the+Presence+of+Loop+Delay+Error