一种改进的PMF-FFT短码捕获方法  

An Improved PMF-FFT C/A Code Acquisition Method

作　　者：余湋[1] 

机构地区：[1]中国西南电子技术研究所,成都610036

出　　处：《电讯技术》2009年第2期60-63,共4页Telecommunication Engineering

摘　　要：提出了一种改进的PMF-FFT短码快速捕获方法。该方法将大规模并行相关器与PMF-FFT捕获结构结合起来,利用大规模并行相关器实现接收信号与本地码的分段匹配相关,将部分相关结果进行FFT运算实现对信号载波频偏的搜索,大大提高了PMF-FFT的捕获速度。Matlab仿真结果表明,该方法可以在低的信噪比之下实现对GPS短码的快速捕获。捕获电路的设计基于流水线,资源复用等硬件设计思想,利用较少FPGA资源,在一片FPGA内实现了对短扩频码的实时的快速捕获。This paper introduces an improved PMF-FFT （ Partial Match Filter-Fast Fourier Transform ） correlator structure for C/A （coarse/acquisition） code acquisition, which is based on the integrated structure of massive parallel correlator and PMF-FFT-correlator. Massive parallel correlator calculates a group of correlation results of received GPS signal and the C/A code in different phases and FFF searchs the carrier doppler frequency. Based on this structure, the correlator can achieve fast acquisition. In low SNR environment, Matlab simulation results indicate that the improved PMF-FFT correlaor can acquire the C/A code correctly and fast. The correlator can be embedded in a chip of FPGA based on the pipeline and resource sharing designing thoughts.

关 键 词：GPS接收机 短码捕获 大规模并行相关器 快速傅里叶变换 

分 类 号：TN965[电子电信—信号与信息处理] TP393[电子电信—信息与通信工程]