Funding for this research was provided by:
Joint Fund of Civil Aviation Research (U1733103)
Department of Science and Technology of Sichuan Province (2016JY0106)
Education Department of Sichuan Province (16ZA0209)
College of Electronic Engineering of CUIT (the 2018 Innovation and Entrepreneurship Project)
Received: 27 February 2019
Accepted: 3 May 2019
First Online: 3 June 2019
: The authors declare that they have no competing interests.
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