| 摘要: |
| 为了减少在高动态、长积分时间环境下全球卫星导航系统（Global Navigation Satellite System,GNSS)信号检测方法在估计参数时的计算量，提出了适用于高动态环境的低复杂度GNSS捕获方法（Low-computation GNSS Acquisition Method，LGAM），将同步多普勒频率假设检验方法（Synthesized Doppler Frequency Hypothesis Testing，SDHT）应用于具有多普勒变化率和比特翻转的高动态GNSS信号捕获中。首先，通过多普勒粗搜索来实现稀疏多普勒（Sparse Doppler Frequency，SDF）过程，并且基于SDF信号结构，推导了后相关信号模型。然后，为了提高多普勒和多普勒变化率检测效率，提出了基于后相关信号模型的双快速傅里叶变换（Fast Fourier Transform，FFT）参数估计方法。实验结果表明，在高动态环境下，信噪比（Signal-to-Noise Ratio，SNR）高于-43 dB时，基于FFT方法的计算量是LGAM1的15倍，是LGAM2的780倍。 |
| 关键词: GNSS 高动态环境 压缩捕获 频率参数估计 |
| DOI：10.20079/j.issn.1001-893x.240429001 |
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| 基金项目: |
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| A Low-computation GNSS Acquisition Method Based on Synthesized Doppler Frequency Hypotheses |
| WU Yi,WU Chao,QIAN Feijie,LIN Xiuwei |
| (School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China) |
| Abstract: |
| To reduce the computations of parameters estimation in high-dynamic and long integration global navigation satellite system(GNSS) signal detection applications,the authors propose a low-computation GNSS acquisition method(LGAM) suitable for high-dynamic environment.The goal of LGAM is to apply the synthetic Doppler frequency hypothesis testing(SDHT) method to the acquisition of high dynamic GNSS signals with Doppler rate and bit flipping.Firstly,sparse Doppler frequency(SDF) process is implemented by coarse Doppler estimation,and post-correlation signal model is derived based on SDF structure.Then,in order to improve the detection efficiency of Doppler and Doppler rate,double-FFT based detection is proposed based on the post-correlation signal model for parameters estimation.The results demonstrate that in high dynamic environments,when the signal-to-noise ratio(SNR) is higher than -43 dB,the computational complexity based on FFT method is 15 times that of LGAM1 and 780 times that of LGAM2. |
| Key words: GNSS high-dynamic environment compressed acquisition frequency parameters estimation |
