基于FFT的扩频码快捕模块的设计实现

介绍基于FFT的扩频码快速捕获原理,给出一种利用探测数据跳变来降低数据调制带来的检测信噪比损失的方法,并对快捕模块的核心单元——采样率转换单元和FFT/IFFT计算单元的FPGA实现进行详细的论述。仿真和实验结果表明,该方法在高数据率调制和低信噪比的情况下实现了扩频码的快速捕获和硬件资源的合理利用。

Design and Implementation of Rapid Code Acquisition Module Based on FFT

This paper introduces the theory of rapid code acquisition based on FFT,and puts forward a data edge detecting method to reduce the detecting SNR loss caused by data modulation.The FPGA implementation of two important modules,sampling rate conversion module and FFT/IFFT calculation module,is described in detail.Simulation results show that this method implements the PN code rapid acquisition and reasonable hardware resource utilization under the low signal-noise ratio and high data modulation rate.