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Pre-distorter Method Using LUT with 2ι Partition Interpolation in the OFDM System  

권오주 (국방과학연구소 위성통신 연구실)
이호근 (경북대학교 전자전기공학부)
하영호 (경북대학교 전자전기공학부)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.27, no.7A, 2002 , pp. 668-675 More about this Journal
Abstract
This paper proposes pre-distorter combined LUT with 2ιpartition interpolation method to reduce nonlinear distortion which was caused by high PAPR and to update LUT quickly. Pre-distorted gain and phase can be found by using LUT which consisted of AM/AM and AM/PM value, and OFDM signal amplitude. The proposed 2ιpartition interpolation can accurately find predistorted gain and phase using bit shift and add component instead of increasing size of LUT which requires increasing the amount of computation. The performance of the proposed method was measured by the difference between HPA input and output characteristics by the LUT size, constellation, SER performance by the HPA, and LUT update error by the HPA characteristic changes. As a result, it is shown that when the size of the LUT is 32 and 64 for 16-QAM and 64-QAM, nonlinear distortion nearly didn't occurred.
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