Joint Estimation and Compensation of Carrier Frequency Offset and I/Q Imbalance in OFDM Systems

• Main Authors: Jheng-RuLiang, 梁正儒
• Other Authors: Chih-Hung Kuo
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/37308138960301265049

碩士 === 國立成功大學 === 電機工程學系碩博士班 === 98 === In this thesis, we consider two non-ideal effects in orthogonal frequency division multiplexing (OFDM) system: carrier frequency offset (CFO) and IQ imbalance. Both CFO and IQ imbalance degrade the system performance seriously. Current joint estimation algorithms need iterations to converge in the estimation, or their computational complexity are considerably high. As a result, we proposed a LS-based method to estimate both CFO and IQ imbalance based on the two identical sequences in the preamble. Simulation results show that it is robust for a wide SNR range both in CFO and IQ imbalance estimation. The performance of IQ imbalance estimation is robust even with gain error 3dB, phase error 20°. Moreover, the proposed method has much lower complexity than the EM-based approach.