实现微弱GPS信号快速捕获的改进算法

发布时间：2018-03-12 07:25

本文选题：弱信号　切入点：捕获　出处：《电视技术》2016年02期 　论文类型：期刊论文

【摘要】：为了能够在低信噪比下实现微弱信号的快速捕获,必须增加处理增益。要提高增益就要进行累积,而累积易受导航电文翻转和多普勒频偏的影响。为了克服两者的影响,传统的捕获方法通常采用相干加非相干累加的捕获算法,但是非相干累加又引入了平方损耗,并且对频率走动效应补偿有限。随着积分时间长度的加长,数据翻转和多普勒变化的影响会愈加突出,传统的算法已不能满足要求。对此,一种新的弱信号快速捕获算法被提出。该算法采用奇偶相间分别相干累加的方法进行数据补偿和并行多普勒搜索的方法进行多普勒补偿,从而在尽量延长单次相干积分时间的基础上,实现了多次相干积分结果的多次相干累加。最后计算机仿真验证,该方法是有效的和正确的,并且与传统方法相比,同样条件下,改进算法的累加次数是传统算法的1/8,捕获时间缩短了1/4以上。
[Abstract]:In order to achieve fast acquisition of weak signals at low SNR, processing gain must be increased. In order to increase the gain, it is necessary to accumulate, which is vulnerable to the effects of navigation message flipping and Doppler frequency offset. The traditional acquisition method usually adopts the coherent plus incoherent accumulation algorithm, but the incoherent accumulation introduces the square loss, and the compensation for the frequency walk effect is limited. The effect of data inversion and Doppler changes will become more and more prominent, and the traditional algorithms can no longer meet the requirements. A new fast acquisition algorithm for weak signals is proposed, in which data compensation and parallel Doppler search are used to compensate the data. On the basis of prolonging the time of single coherent integration as far as possible, the multiple coherent accumulation of the result of multiple coherent integration is realized. Finally, the computer simulation proves that the method is effective and correct, and compared with the traditional method, under the same conditions, The cumulative times of the improved algorithm are 1 / 8 of the traditional algorithm, and the acquisition time is reduced by more than 1/4.
【作者单位】：西安邮电大学通信与信息工程学院;中国空间技术研究院西安分院;
【基金】：国家自然科学基金项目(61201194) 陕西省自然科学基础研究计划项目(2014JQ8318)
【分类号】：P228.4

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