扩频信号快捕算法硬件设计与实现

为提高扩频信号捕获门限及伪码相位捕获准确度 ,在多通道并行捕获技术的基础上介绍块匹配算法和单点多次平滑算法两种相关峰检测方法 ,并在以 FPGA和 DSP为核心的单板系统上实现。其中单点多次平滑算法已应用于工程实际中的软件数据处理算法。实践表明 ,该方法有效地提高了检测门限 2 d B。在 FPGA数字电路设计实现中 ,提出了多个并行捕获通道共用一个载波 NCO,一个伪码 NCO及伪码产生器的方法 ,大大节省了硬件资源 ,在规模为 1.6万门的 FPGA芯片内共设计码并行快捕通道 12 8个。

Design and Implementation of Rapid Acquisition Algorithm of Spread-spectrum Signals on Chip

In order to improve the detection threshold of spread-spectrum signal and the capture accuracy of PN code phase,two algorithms about correlation peak detecting,based on the technique of multi-channels parallel acquisition are presented in this paper.These two algorithms have been realized on chip and the results shows that one of the algorithms can improve detection threshold 2dB effectively.In order to save the FPGA resource,the paper also presents a method that all parallel channels use single carrier NCO,single PN code NCO and PN code generator in common,With the method,we realize 128 PN code parallel acquisition channels in a FPGA chip.