基于稀疏傅里叶变换的快速捕获方法

卫星信号捕获是接收机内基带信号处理的关键步骤，捕获的速度严重影响接收机首次定位的时间（TTFF）。在基于快速傅里叶变换（FFT）的并行码相位捕获（PCPS）方法基础上，将具有亚线性运算量的稀疏傅里叶变换（SFT）引入捕获过程中，提出了基于SFT的快速捕获方法，通过优化捕获过程中相关运算的效率，提高捕获速度。仿真结果表明，与传统的基于FFT的捕获方法相比，基于SFT的快速捕获方法运算效率提高到原来的2倍，更好地满足了卫星信号对快速捕获的要求。

Fast acquisition methods based on sparse Fourier transform

The acquisition of the satellite signals is the key step of baseband signal processing in the re-ceiver.The speed of the acquisition has a serious effect on the time to first fix(TTFF).According to the par-allel code phase search(PCPS)method based on fast Fourier transform(FFT),the sparse Fourier transform (SFT)which computes in sub-sampled time is applied to the PCPS algorithm to simplify the acquisition process.The fast acquisition method based on SFT is proposed.The faster acquisition is achieved by optimi-zing the efficiency of correlation operation.The simulation results show that the computation time of the pro-posed fast acquisition method based on SFT is 2 times faster than that of the conventional FFT-based acquisi-tion method.And it can better meet the requirements of fast satellite signal acquisition.