Mutual Interference Suppression and Signal Restoration in Automotive FMCW Radar Systems

Sohee LIM  Seongwook LEE  Jung-Hwan CHOI  Jungmin YOON  Seong-Cheol KIM  

Publication
IEICE TRANSACTIONS on Communications   Vol.E102-B   No.6   pp.1198-1208
Publication Date: 2019/06/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2018EBP3175
Type of Manuscript: PAPER
Category: Electromagnetic Compatibility(EMC)
Keyword: 
automotive radars,  frequency modulated continuous wave (FMCW),  mutual interference suppression,  signal restoration,  

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Summary: 
This paper presents an interference suppression and signal restoration technique that can create the clean signals required by automotive frequency-modulated continuous wave radar systems. When a radar signal from another radar system interferes with own transmitted radar signal, the target detection performance is degraded. This is because the beat frequency corresponding to the target cannot be estimated owing to the increase in the noise floor. In this case, advanced weighted-envelope normalization or wavelet denoising can be used to mitigate the effect of the interference; however, these methods can also lead to the loss of the desired signal containing the range and velocity information of the target. Therefore, we propose a method based on an autoregressive model to restore a signal damaged by mutual interference. The method uses signals that are not influenced by the interference to restore the signal. In experiments conducted using two different automotive radar systems, our proposed method is demonstrated to effectively suppress the interference and restore the desired signal. As a result, the noise floor resulting from the mutual interference was lowered and the beat frequency corresponding to the desired target was accurately estimated.