软件GPS接收机弱信号捕获方法

为了提高软件GPS接收机弱信号捕获能力,研究了软件GPS接收机弱信号捕获的方法,分析了非相干积分的损耗和增益,通过非相干积分方法提高接收机灵敏度,对于存在多普勒频移的信号采用频率补偿方法改善非相干积分效果,采用实验方法确定检测门限,达到较好的检测效果。采用平方法测量精确频率,分析了不同条件下平方法的输出增益,仿真实验证明,合理选择数据长度和求和时间可以较大程度地改善频率分辨率。

Method for Weak Signal Acquisition of GPS Software Receiver

In order to improve the acquisition capability of GPS receiver based on software,a method for acquisition of weak signals of GPS receiver based on software is studied.The loss and gain of noncoherent integration are analyzed,and the receiver sensitivity is improved by noncoherent integration.For signals with Doppler shift,the effect of noncoherent integration is improved by frequency compensation.The detection threshold is determined through experiment and good detection effect is achieved.The accurate frequency is measured through squaring method,and the output gains for different data lengths are analyzed.It is proved that appropriate data length and summing time can improve the frequency resolution significantly.