中文摘要：

在城市街道、峡谷、森林等环境里,GPS信号变得十分微弱。针对这些弱信号环境下捕获GPS信号的问题,将差分累积应用于GPS信号的检测。由于差分累积具有较大的多普勒频移容差,因此在克服由载波频移带来的累积衰减上具有优势。更主要地考虑到了不同的GPS信号捕获环境下,噪声背景的强度会发生变化。噪声强度的变化需要接收机自适应地调整GPS信号的检测门限,以保持良好的检测性能。本文创新地提出了,基于差分累积量的GPS信号自适应检测算法,提出了相应的接收机的实现结构,以传统结构做参照分析了新的差分累积自适应检测结构所具有的优势。在文章最后部分,通过仿真验证了本文提出方法的有效性,实验结果表明新提出的GPS信号检测结构具有良好并且稳定的检测性能。

英文摘要：

In the environments,urban street,canyon,dense woods,the strength of GPS signal becomes extremely weak.To acquire the degraded GPS signal in the environment without light-of-sight signal,differential accumulation is employed to detect GPS signal.Since of huge tolerance on Doppler shift,GPS signal detection based on differential accumulation effectively brings the decrease on the correlation loss from Doppler shift.More importantly,the main work of this paper focuses on the variance of noise background.The change of noise level will inevitably induce the modification on the threshold of GPS receiver,to guarantee the stable detection performance.This paper proposes a novel GPS signal adaptive detection structure based on differential accumulation.The contribution lies on the proposed block of GPS receiver based on differential accumulation,study on the deduction of detection performance and the determination of adaptive threshold.In the final part of this paper,simulation is carried out to test the effectiveness of the proposed method,and the results demonstrate excellent and stable performance on the detection probability.