GLONASS捕获系统中FFT核复用关键问题  

Critical Problems about FFT Core Reuse in GLONASS Acquisition System

作　　者：耿建平[1] 朱剑飞[1] 纪元法[2] 孙希延[3] 

机构地区：[1]桂林电子科技大学电子工程与自动化学院,桂林541004 [2]桂林电子科技大学应用科技学院,桂林541004 [3]桂林电子科技大学信息与通信学院,桂林541004

出　　处：《计算机系统应用》2012年第9期128-132,共5页Computer Systems & Applications

基　　金：国家重点基础研究发展技术计划(973)(2007CB815500);国家自然科学基金(60802018;61062003);广西高校优秀人才资助项目;桂林电子科技大学人才专项基金

摘　　要：根据GLONASS卫星信号组成和特性及其伪码捕获原理,运用并行码相位捕获算法在MATLAB环境下完成GLONASS卫星信号的捕获仿真,同时根据MATLAB下建立的仿真平台,设计了基于此方法的FPGA具体实现电路;为了满足FFT运算点数的要求,采用数据Sinc内插滤波器对数据进行精确内插,将输入的62000点数据内插为4096点,同时为了复用FFT核,分别采用了加快C/A码读取速度的方法、运用状态机的状态值加上数据指数项的数据截位方法;最后通过Xilinx的ISE软件调用Modelsim对整个捕获模块进行仿真.仿真结果表明:该系统实现了GLONASS信号的捕获,满足了接收机系统功能和性能的要求,可直接用于GLONASS实时接收机系统的设计中.According to the characteristics of GLONASS satellite signal and the principles of PR code acquisition, the acquisition of GLONASS signal using parallel code phase acquisition algorithm based on FFT are simulated in MATLAB, on the basis of simulation platform established in MATLAB, the FPGA implementation of GLONASS PR code signal acquisition system based on the parallel code phase acquisition is designed; Meanwhile, the Sine data interpolation filter is used to implement the precise data interpolation to satisfy the demand for FFT transformation by interpolating the inputted 62000 points to 4096 points which is transferred to FFT-IFFT module, and in order to reuse the FFT core, the method of accelerating the read speed of the C/A code and the method of using the state value of the FSM and the exponent of the data to intercept the data bits are used. At last the whole acquisition module are verified by the simulation of Xilinx＇s ISE calling ModelSim software. The simulation results show that the system can acquire the GLONASS signal. It is concluded that the designed system can satisfy the requested function and performance of receiver system, and can be used in the real-time GLONASS receiver system.

关 键 词：GLONASS 并行码相位搜索捕获 FFT核 FPGA 

分 类 号：TN967.1[电子电信—信号与信息处理]