基于DSP+FPGA的高动态GPS信号载波环路设计  

Carrier Loop Design for High-dynamic GPS Signal Based on DSP+FPGA

作　　者：胡锐[1] 薛晓中[1] 孙瑞胜[1] 段笑菊[1] 

机构地区：[1]南京理工大学动力工程学院,江苏南京210094

出　　处：《南京理工大学学报》2010年第1期75-79,共5页Journal of Nanjing University of Science and Technology

基　　金：国家"863"计划资助项目(2009AA12Z321)

摘　　要：为了提高动态环境下捕获、跟踪GPS信号的环路性能,通过分析环路逻辑时序、参数和高动态下多普勒频移的变化特性,使用高阶、宽带宽的跟踪环路,设计了一种基于DSP+FPGA的载波捕获、跟踪方法。利用现场可编程门阵列(FPGA)对信号进行傅里叶变换,实现载波的快速初捕和二次精捕,同时利用数字信号处理器(DSP)实现具有自动调整功能的二阶频率锁定环路的辅助三阶Costas-PLL载波跟踪环,使得环路具有抗高动态性能的同时仍拥有较高的跟踪精度。仿真实验表明:该方案能实现高动态下载波信号的快速捕获与精确跟踪。In order to improve GPS signal＇s acquisition, tracking performance in a high dynamic environment, the sequential logic, loop parameters and high dynamic changes under the Doppler frequency shift are analysed. The wide bandwidth and high-order tracking loop is used. A loop to carri- er acquisition and tracking is designed based on DSP ＋ FPGA. By signal＇s Fourier transform, field programmable gate array （FPGA） is used to complete fast carrier first capture and second precise acquisition, while digital signal processor （DSP） is used to realize an automatically adjusted secondorder FLL-assisted third-order Costas-PLL which makes the loop have the anti-high dynamic performance and still have a high tracking accuracy. Simulation results show that the design can achieve GPS carrier＇s fast acquisition and accurate tracking in high dynamic environment.

关 键 词：高动态 全球定位系统信号 载波捕获 载波跟踪 频率锁定环路 Costas-PLL 

分 类 号：TN914.42[电子电信—通信与信息系统]