A performance analysis of optimized semi-blindchannel estimation method in OFDM systems
Sangirov Gulomjon*, Fu Yongqing*, Jamshid Sangirov**, Fang Ye* and Ahmad Olmasov****Information and Communication Engineering College, Harbin Engineering University, Harbin, 150001 China**Samsung Electronics, South Korea***Samarkand branch of Tashkent University of Information Technologies, Uzbekistan
gulomjons@hrbeu.edu.cn

Abstract — Nowadays, one of the effectively used technique in wireless communication area is an orthogonal frequency divisionmultiplexing (OFDM). In OFDM systems, channel impairments due to multipath dispersive wireless channels can cause deep fades inwireless channels. Therefore, an accurate and computationally eﬃcient channel state information necessary when coherent detection
is involved in the OFDM receiver. Hence, it is essential to have a good channel estimation method for OFDM systems in wirelesscommunication. And normally one of the good channel estimation methods is a semi-blind channel estimation. On the other hand, thesemi-blind method requires a large number of processing operations. In order to avoid the high complexity of the existing method,
the semi-blind channel estimation has been optimized. At the receiver side, we calculate subspace decomposition for blind channel
estimation and further to improve channel estimation we use training based technique to estimate channel state information. Next we
combine these channel estimations as semi-blind channel estimation methods and we optimized semi-blind channel estimation bychoosing optimal technique for training based channel estimation.
Keyword—Semi-blind channel estimation, OFDM, least square and scaled LS
Gulomjon Sangirov received the M.S. degrees in Information and Communication Engineering from Harbin Engineering
University in 2012. And he is studying Ph.D. in College of Information and Communication Engineering in Harbin Engineering
University, China currently. His research interests are Channel Estimation in MIMO-OFDM and Quasi-Cyclic-LDPC coding.

Yongqing Fu received the MS degree in electrical engineering from National University of Defense Technology, Changsha, Chinain 1985. He held the posts of Lecturer (1988-1995), Associate professor (1995-2000) and Professor (since 2000) in the ElectricalEngineering Department, Harbin Engineering University. He was a visiting Professor in Electrical and Computer Engineering
Department, University of Manitoba, Canada in 2002 and also Electrical and Computer Engineering Department, University ofCalifornia, San Diego, USA in 2009. He is the author of four books, more than 100 articles, and more than 10 patents. His researchinterests include the weak signal detection, chaotic communication and signal processing, cognitive radio system, image coding,marching and feature extraction and circuit and electronic system. Prof. Fu is the Vice director of the Northeast Electric Theory
Association (since 2003), and he is a reviewer for the Journal of China Universities of Posts and Telecommunications (since 2006).

Jamshid Sangirov received the M.S. degrees in Information and Communication Engineering from Yeungnam University in2006. He got his Ph.D. in Information and Communication Engineering at Korean Advanced Institute of Science and Technology(KAIST) at 2013. He worked with the RFIC Design Team, at Teltron Inc., Korea, from 2010 to 2011. From 2013 he is withSamsung Electronics. His research interests are analog/RF/VLSI and high-speed IC design.

Fang Ye received her Ph.D. degree in Communication and Information System from Harbin Engineering University in 2006. FromNovember 2007 to November 2008, she has been as a visiting scholar in the school of electronics and computer science, University
Of Southampton, U.K. Since December 2008, she is an associate professor of the school of Information and Communication
Engineering in Harbin Engineering University, China. Her research interests include LTE technologies, adaptive radio resource
allocation technology and UWB signal processing. She is member of IEEE and Association for Computing Machinery (ACM).

Ahmad Olmasov received the M.S. degrees in Tashkent University of Information Technologies, Tashkent, Uzbekistan in 2007.
And he started working with Samarkand branch of Tashkent University of Information Technologies. Currently, he is a lecturer indepartment of telecommunication engineering at Samarkand branch of Tashkent University of Information Technologies. His
research interests are Mobile communication, channel coding in high throughput wireless communication and MIMO-OFDM.