상세정보
학술지
Digitally Assisted Feedforward Compensation of Cartesian-Feedback Power-Amplifier Systems
- 저자
- 부현호, SungWon Chung, Joel L. Dawson
- 발행일
- 201108
- 출처
- IEEE Transactions on Circuits and Systems II : Express Briefs, v.58 no.8, pp.457-461
- ISSN
- 1549-7747
- 출판사
- IEEE
- 협약과제
- 11MB1500, 차세대 무선 융합 단말용 Advanced Digital RF 기술 개발, 유현규
- 초록
- This brief describes digitally assisted feedforward compensation to extend the bandwidth and to enhance the in-band linearity of Cartesian-feedback (CFB) power-amplifier (PA) systems. The proposed technique combines the strength of the CFB, which is chiefly relaxed PA modeling requirements, with the increased speed of digital predistortion (DPD). CFB is used initially to train efficiently a lookup table for a predistorted feedforward path. Then, both the CFB and the predistorted feedforward path run simultaneously during transmission. Viewed as a bandwidth-enhancement technique for analog CFB, the feedforward-compensated system shows a linearization bandwidth improvement of almost six times over the unaided feedback system. Viewed as a means of improving the in-band linearity of CFB, the proposed system realizes up to 10 dB of reduction in distortion products over CFB or DPD alone and does so without compromising the stability of the feedback system. © 2011 IEEE.
- KSP 제안 키워드
- Bandwidth improvement, Feedback systems, Feedforward Compensation, digital predistortion(DPD), digitally assisted, in-band, look-up table