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。
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 transforma- tion 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 sig- nal acquisition method is proposed. Simulation results prove that the proposed method can improve the receiving performances of GPS in mulfipath interference environment by means of Monte-Carlo.
出处
《南京理工大学学报》
EI
CAS
CSCD
北大核心
2009年第1期64-68,共5页
Journal of Nanjing University of Science and Technology
关键词
多径干扰
全球定位系统
弱信号
高灵敏度
接收机
频域相关
差分累积
muhipath interference
global positioning system
weak signals
high sensitivity
receivers
frequency domain correlation
difference accumulation