| 摘要: |
| 抑制多径干扰是提高GPS定位精度的关键。针对低载噪比、预相关带宽有限的情况下斜率估计（ELS）的多径抑制技术往往不能正常工作的问题，提出了一种基于能够鲁棒地提取直线斜率的随机Hough变换（RHT）的斜率估计多径抑制算法。该算法主要采用多相关器结构得到多径相关峰的采样值，然后利用RHT得到相关峰两边的斜率，最后结合ELS的基本原理构成具有补偿因子的伪码鉴相器，以达到抑制多径干扰的目的。仿真结果表明，该算法解决了ELS在有限的预相关带宽（4 MHz）和较低载噪比(33 dB-Hz)条件下不能有效提取直线斜率的问题，并且在相同载噪比(44 dB-Hz)条件下，该算法的多径抑制性能也优于ELS算法。 |
| 关键词: GPS 信号传输 多径抑制 斜率估计 随机Hough变换 低载噪比 |
| DOI： |
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| 基金项目:江西省教育厅科学技术研究项目（GJJ10458）;江西省科技支撑计划项目（20123BBE50098） |
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| A slope estimation multipath mitigation algorithm based on randomized Hough transform |
| HU Hui,FANG Ling,LIU Ying-ying |
| () |
| Abstract: |
| The multipath mitigation is the key to improve GPS positioning precision.As the early late slope(ELS) multipath mitigation can not work well under the circumstances of low carrier to noise ratio and narrow pre-correlation bandwidth,a new slope estimation multipath mitigation algorithm is proposed based on randomized Hough transform(RHT) to estimate the straight line′s slope robustly.The algorithm gets the sampling values of multipath correlation peak by using multiple correlators.Then the slope on both sides of correlation peak is obtained by using RHT.Finally the phase discriminator with compensating factor is formed based on the basic principle of ELS to suppress multipath interference.Theoretical analysis and simulation results show that the algorithm solves the problem that ELS can′t work well under the condition of narrow bandwidth(4 MHz) and low carrier to noise ratio (33 dB-Hz).And the algorithm also has superior capability of multipath mitigation than ELS in the same carrier to noise ratio(44 dB-Hz). |
| Key words: GPS signal transmission multipath mitigation slope estimation randomized Hough transform low carrier to noise ratio |
