Constellation Extension Techniques Based on Convex Optimization for OFDM Systems

• Main Authors: Chen, You-Yen, 陳囿嚴
• Other Authors: Wang, Chin-Liang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/24418153407342718456

碩士 === 國立清華大學 === 通訊工程研究所 === 102 === In this thesis, we propose a novel constellation extension (CE) scheme for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. Traditionally, most PAPR reduction schemes are designed to minimize the peak value of the transmitted time-domain OFDM signal as low as possible; however, it has been shown in [1] that maximization of the signal-to-distortion ratio (SDR) is a better criterion than minimization of the PAPR because it can achieve better bit error rate (BER) performance. In the proposed CE scheme, different from the most previous CE schemes, all the constellation points are allowed to be shrunk as well as to be extended for maximizing the SDR via solving a convex optimization problem. Furthermore, we separately consider the extension or shrinking of the real and imaginary parts of a constellation point since their contributions to the time-domain peak samples are different. These features result in an improvement in terms of both BER and PAPR with a slightly increase in the computational complexity as compared to the state of the art scheme in [1].