|Abstract:||An important class of signal distortions arises from the imperfections associated with the RF front-ends, and an important part of the RF front-end distortion can be modelled as linear signal distortion. Amplitude distortion is one important form of linear signal distortion, and phase distortion, also known as non-uniform group delay, is the other form of linear signal distortion, and both distortions limit the ability of a user receiver to combine different frequency components and degrade its performance. Dual BPSK Tracking (DBT) technique treats BOC signal as a sum of two coherent BPSK signals, which are located at its upper and lower sidebands, respectively. And it combines these two components with different center frequencies to restore code delay and sub-carrier phase and carrier phase and finally form code, sub-carrier and carrier tracking loops. Therefore, the coherence between the upper and lower sidebands is vital for DBT technique to process BOC signal and the distortions due to the RF front-end imperfections have a greater impact on DBT technique than other techniques, especially when processing highorder BOC signal as the upper and lower sidebands are largely separate in frequency domain. Considering the fact that the bandwidth of a single sideband is much narrower than the overall bandwidth for high-order BOC signal, this paper assumes a perfect amplitude response and phase response on either sideband and focuses on the asymmetry of the RF front-end on the upper and lower sidebands. This paper introduces two different mathematical models to respectively describe the effects of the particular amplitude distortion and phase distortion on BOC signal, and reveals how the distortions affect performance of DBT receivers and relates levels of the distortions to the resulting measurements. Theoretical analysis and numerical simulations show that the amplitude distortion causes no measurement biases but results in coupling effect across carrier and subcarrier measurements, and the phase distortion degrades code tracking performance and leads to fixed biases on both sub-carrier and carrier measurements.|
Proceedings of the 2016 International Technical Meeting of The Institute of Navigation
January 25 - 28, 2016
Hyatt Regency Monterey
|Pages:||820 - 828|
|Cite this article:||
Zhu, Yonghui, Cui, Xiaowei, Shen, Jiannan, Lu, Mingquan, "Effects of Linear RF Front-end Distortions on High-order BOC Signal Processing Using DBT Technique," Proceedings of the 2016 International Technical Meeting of The Institute of Navigation, Monterey, California, January 2016, pp. 820-828.
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