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An Analytical Model for BDS B1 Spreading Code Self-Interference Evaluation Considering NH Code Effects
Xin Zhang1, Xingqun Zhan2, Shaojun Feng3
1School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, China. xin.zhang@sjtu.edu.cn.
Sensors (Basel, Switzerland)
|March 24, 2017
Summary
BeiDou Navigation Satellite System (BDS) B1-I and GPS signals suffer from self-interference due to short spreading codes. A new analytical model accurately predicts this interference, crucial for high-sensitivity applications.
Area of Science:
- Satellite Navigation Systems
- Signal Processing
- Radio Frequency Engineering
Background:
- Short spreading codes in BeiDou Navigation Satellite System (BDS) B1-I and GPS Coarse/Acquisition (C/A) signals cause self-interference.
- Existing models do not fully address BDS B1-I self-interference, especially with its unique Neumann-Hoffmann (NH) code.
Purpose of the Study:
- To develop and validate a novel analytical model for BDS B1-I self-interference.
- To quantify the impact of self-interference on BDS receiver performance.
Main Methods:
- Extended a GPS C/A code self-interference model to incorporate BDS B1-I specific features, including the NH code.
- Developed a three-parameter analytical model using spectral separation coefficient (SSC) and equivalent white noise power.
- Validated the model with hardware and software simulator data, analyzing cyclostationarity for accuracy.
Main Results:
- The proposed model accurately predicts BDS B1-I self-interference.
- Self-interference significantly increases receiver noise floor (up to 3.83 dB) and code tracking error (up to 11.65 m) under low carrier-to-noise density ratio (C/N₀) conditions.
- The most significant impact occurs when differential Doppler between signals is zero.
Conclusions:
- The developed analytical model provides crucial insights into BDS B1-I self-interference.
- Self-interference poses a significant challenge for high-sensitivity satellite navigation applications.
- The findings highlight the inherent weakness of short codes in satellite navigation systems.
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