Journal of Systems Engineering and Electronics ›› 2021, Vol. 32 ›› Issue (3): 573-583.doi: 10.23919/JSEE.2021.000049

• DEFENCE ELECTRONICS TECHNOLOGY • Previous Articles     Next Articles

Adaptive digital self-interference cancellation based on fractional order LMS in LFMCW radar

Yongjiang LUO*(), Luhao BI(), Dong ZHAO()   

  1. 1 School of Electronic Engineering, Xidian University, Xi’an 710071, China
  • Received:2020-07-22 Online:2021-06-18 Published:2021-07-26
  • Contact: Yongjiang LUO E-mail:yjluo@mail.xidian.edu.cn;bluhao@163.com;zhaod923@163.com
  • About author:|LUO Yongjiang was born in 1979. He received his Ph.D. degree in electronic science and technology from Xidian University, Xi’an, China in 2011. He is currently an associate professor in electro-nic science and technology, Xidian University. His current interests include wideband signal processing, intelligent information processing, fractional systems and signal processing. E-mail: yjluo@mail.xidian.edu.cn||BI Luhao was born in 1995. He received his B.S. degree in electronic information science and technology from Qingdao University of Technology, Qingdao, China in 2017. He received his M.S. degree in the School of Electronic Engineering, Xidian University, Xi’an, China in 2020. His research interest is radar signal processing. E-mail: bluhao@163.com||ZHAO Dong was born in 1996. He received his B.S. degree in electronic science and technology from Xi’an University of Posts & Telecommunications, Xi’an, China in 2019. He is currently pursing his M.S. degree in the School of Electronic Engineering, Xidian University, Xi’an, China. His research interest is fractional signal processing. E-mail: zhaod923@163.com

Abstract:

Adaptive digital self-interference cancellation (ADSIC) is a significant method to suppress self-interference and improve the performance of the linear frequency modulated continuous wave (LFMCW) radar. Due to efficient implementation structure, the conventional method based on least mean square (LMS) is widely used, but its performance is not sufficient for LFMCW radar. To achieve a better self-interference cancellation (SIC) result and more optimal radar performance, we present an ADSIC method based on fractional order LMS (FOLMS), which utilizes the multi-path cancellation structure and adaptively updates the weight coefficients of the cancellation system. First, we derive the iterative expression of the weight coefficients by using the fractional order derivative and short-term memory principle. Then, to solve the problem that it is difficult to select the parameters of the proposed method due to the non-stationary characteristics of radar transmitted signals, we construct the performance evaluation model of LFMCW radar, and analyze the relationship between the mean square deviation and the parameters of FOLMS. Finally, the theoretical analysis and simulation results show that the proposed method has a better SIC performance than the conventional methods.

Key words: adaptive digital self-interference cancellation (ADSIC), linear frequency modulated continuous wave (LFMCW) radar, fractional order least mean square (LMS)