Abstract: Weak signal detection algorithm is key of high sensitivity GPS positioning, several acquisition algorithms in low signal to noise ratio environment, including no-coherent integration of coherent integration, circle correlation integration and differential coherent integration are analyzed, signal process flows are discussed, algorithm acquisition performance are studied by simulation. The theoretical analysis and simulation result show that several algorithms can improve acquisition sensitivity of receiver, and differential coherent integration is capable of detecting GPS signals in low signal to noise ratio environment.

Key words: Global Positioning System（GPS）, detection, low signal to noise ratio, indoor

摘要： 弱信号检测算法是高灵敏度GPS定位的核心，对低信噪比环境下的相关累加结合非相关累加、圆周相关累加以及差分相关累加捕获算法进行了理论分析，对信号捕获流程进行了讨论，重点对算法捕获性能进行了仿真。根据理论分析和仿真结果可以看出，所讨论的几种算法都能够在一定程度上提高接收机的捕获灵敏度，差分相关累加捕获算法更适合检测低信噪比环境下的GPS信号。

关键词: 全球定位系统（GPS）, 检测, 低信噪比, 室内