Performance Improvement of Carrier Frequency Offset Estimation Methods in OFDM System

• Main Authors: Dong Hai Yung, 楊東海
• Other Authors: 呂振森
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/r26hrd

碩士 === 國立臺北科技大學 === 電機工程系研究所 === 97 === With increasing demands from users, the issue of bandwidth efficiency becomes more and more important. The OFDM is a modulated technology with high bandwidth efficiency. It can provide high data rates with limited bandwidth. However, one of the drawbacks is their extreme sensitivity to frequency synchronization errors. With slight carrier frequency offset (CFO), it will result in the inter-carrier interference (ICI) which causes severe degradation on the system performances. Therefore, this thesis is mainly to research into the carrier frequency offset estimation methods for the CFO induced by imperfections of local oscillator’s frequency at receiver. A new carrier frequency offset estimation method combined with offset compensation was proposed. This method is based on the recent pilot-based carrier frequency offset estimation method which integrates with maximum likelihood estimation and ICI Self-cancellation algorithm. The proposed method can improve the system’s performance without increasing a lot of complexity under the same bandwidth efficiency. According to the computer simulation, our results show that it can not only extend the estimation rage of carrier frequency offset, but also increase the system performance.