Frequency Offset Estimation via Differentially Coherent Characterization of Frequency Errors for OFDM Communications

• Main Authors: Wei-Chih Tzeng, 曾偉智
• Other Authors: Jia-Chin Lin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/75895615720437086182

碩士 === 國立暨南國際大學 === 電機工程學系 === 92 === A novel frequency offset estimation technique for OFDM wireless communications is proposed in this paper. By taking advantage of subcarrier-level differentially coherent detection, the proposed estimator based on frequency error characteristics can effectively overcome frequency-selective fading effects. Frequency error characterization is achieved by means of pseudo-noise (PN) matched filters (MF) on the subcarrier basis; thus, it inherently needs no assistance in the form of accurate timing information. In addition, the proposed technique can combat the rapid time-selectivity caused by a high Doppler spread because it requires channel stationarity within only a short time duration due to the exploitation of a single training symbol. Furthermore, a linearized estimator is also proposed to reduce the computational complexity, resulting in some insignificant performance degradation. Extensive computer simulations have verified the superiority of the proposed technique.