Carrier Frequency Recovery Technique in OFDM Systems

Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to carrier frequency errors. In this paper, a new method utilizing pilots to do frequency synchronization in frequency domain is proposed with large estimation range. It needs no such prerequisite assumption that a perfect symbol timing synchronization [IEEE Transactions on Communications 42 (1994) 2908; 45 (1997) 1613] has been done before performing integer carrier frequency synchronization. Also, a new adjusting model for fine carrier frequency is proposed. Simulation and performance analysis show that our overall frequency estimator has high accuracy. The corresponding FPGA circuit through test in high definition TV (HDTV) prototype in Team of Expert Engineering Group (TEEG) in China proves its availability and feasibility.Bo Ai (M2001) was born in Shannxi Province in China on February 7, 1974. He received a B.Sc. degree from Engineering Institute of Armed Police Force and a Master degree, a Ph.D degree from Xidian University in 1997, 2002 and 2004 in China respectively. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) of China, and has published over forty papers in his research area till now. He is senior member of Chinese Electronics Institute (CIE), an editorial commitee member of journal of Computer Simulations. His current interests are the research and applications of OFDM technique with emphasis on synchronization.Jian-hua Ge was born in September, 1961 in JiangSu Province in China. He received the B.Sc., Master and Ph.D. degree from Xidian University in 1982, 1985 and 1989 respectively. He is now the professor in both Xidian University in Xian and Shanghai Jiaotong University in Shanghai. He is the senior member of Chinese Electronics Institute. He has won lots of scientific and technical prizes in China and published many papers. His interests are transmission communications and web security.Yong Wang (M2003) was born in Shannxi Province in China in 1976. He received a B.Sc. and Master degree from Xidian University in China in 1997 and 2002 respectively, and is now working towards the Ph.D. degree on communications in the Key Laboratory of ISN in Xidian University. He has once participated in the key research project on HDTV in TEEG of China and his interests are broadband multimedia communications.Dian-fu Zhang was born in Shannxi Province in China in 1954. He received a B.Sc. degree from Xidian University in China in 1977. He is now working as a professor and the chairman of the telecommunication department in Engineering College of Armed Police Force. His interests are mobile communications.Jun Liu was born in Beijing in China in 1963. He received his B.Sc. degree from Nanjing University Of Aeronautics and Astronautics in China in 1984. He is now a professor in Engineering College Of Armed Police Force. His research interests include integrated circuit design and artificial intelligence.