【摘要】 为了提高全球定位系统(GPS)接收机的增益,有必要进行长时间的累积积分。针对累积最重要的限制:导航电文的变化、多谱勒频偏的影响以及非相干累积的平方损失,该文指出在弱信号条件下快速傅立叶变换捕获较传统算法更具有优势。该算法通过采用差分累积,增加累积时间,减轻非相干累积平方带来的增益损失。另外,全比特搜索算法能够估计出导航数据的最佳组合,实现长时间的相干积分。结合这两种算法,提出一套完整的GPS弱信号处理方案。最后进行了Monte-Carlo仿真,仿真试验结果验证了该算法的有效性。更多还原

【Abstract】 In order to enhance the gain of the global positioning system(GPS) receiver,a long integration time is needed.The most challenging problems are navigation data transitions,Doppler frequency error and square loss caused by non-coherent integration.For those bad factors,fast Fourier transformation acquisition has much superiorities than traditional ways.Different coherent integration improves integration time and removes square loss.Full-bit searching method estimates the optimal combination of these navigation data very well.Combining the superiorities of the two algorithms,an improved weak signal acquisition method is proposed.Simulation results prove that the proposed method can improve the receiving performances of GPS in multipath interference environment by means of Monte-Carlo.更多还原