tailieunhanh - Báo cáo hóa học: " Research Article Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 20463 7 pages doi 2007 20463 Research Article Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization Ning Chen 1 G. Tong Zhou 2 and Hua Qian3 1 Freescale Semiconductor Inc. Austin TX 78729 USA 2 School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA 30332 USA 3 Marvell Semiconductor Inc. Santa Clara CA 95054 USA Received 9 June 2005 Revised 14 February 2006 Accepted 24 November 2006 Recommended by Enis Ahmet Cetin Many modern communication signal formats such as orthogonal frequency-division multiplexing OFDM and code-division multiple access CDMA have high peak-to-average power ratios PARs . A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers PAs but also leads to low transmission power efficiency. Selected mapping SLM and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach. Copyright 2007 Ning Chen et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Modern transmission formats such as orthogonal frequency-division multiplexing OFDM and code-division multiple access CDMA have gained tremendous popularity thanks to their high spectral efficiency. However a drawback is the low power efficiency of these systems. OFDM and CDMA signals suffer from high peak-to-average power ratios PARs making them susceptible to nonlinearities that are inherent in the RF microwave power amplifiers PAs . To avoid nonlinear distortions .