Combining the advantages of partial matched filter（PMF） and fast Fourier transform（FFT）,an improved fast acquisition method for GPS C/A code is proposed.According to PMF-FFT acquisition architecture,the greater th...Combining the advantages of partial matched filter（PMF） and fast Fourier transform（FFT）,an improved fast acquisition method for GPS C/A code is proposed.According to PMF-FFT acquisition architecture,the greater the number of PMF will bring out the more slowly amplitude decreasing of the amplitude-frequency response,the smaller scale of the corresponding PMF,and the larger computation of the FFT.In order to compensate the frequency spectrum attenuation caused by spectrum leakage and fence effect,adding window function to PMF-FFT is presented.Through comparing the influences to the acquisition performance based on rectangular,Hamming,Blackman and Rife-Vincent（Ⅲ） window functions,an improved Rife-Vincent Ⅲ windowing algorithm is recommended for the fast acquisition based on PMF-FFT.展开更多
基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提...基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提出基于函数波束形成的改进FFT-FISTA算法。改进算法以函数波束形成输出作为FFT-FISTA算法的迭代输入,建立函数波束形成、声源分布及升幂空间转移不变点扩散函数的线性方程组,基于周期边界条件下的快速傅里叶变换进行迭代求解,使被运算的非周期函数变为一个周期函数,解决补零边界带来的波数泄漏问题,可提高运算准确性,进一步提升成像性能;通过指数运算锐化点扩散函数主瓣,拓展点扩散函数空间转移不变性假设的适用性。仿真和试验结果表明,相较于常规FFT-FISTA算法,改进算法能提升成像空间分辨率及动态范围,扩大FFT-FISTA算法的有效成像区域,压缩气体泄漏试验结果验证了改进算法的有效性。展开更多
基金Supported by the Ministerial Level Foundation(B222006060)
文摘Combining the advantages of partial matched filter（PMF） and fast Fourier transform（FFT）,an improved fast acquisition method for GPS C/A code is proposed.According to PMF-FFT acquisition architecture,the greater the number of PMF will bring out the more slowly amplitude decreasing of the amplitude-frequency response,the smaller scale of the corresponding PMF,and the larger computation of the FFT.In order to compensate the frequency spectrum attenuation caused by spectrum leakage and fence effect,adding window function to PMF-FFT is presented.Through comparing the influences to the acquisition performance based on rectangular,Hamming,Blackman and Rife-Vincent（Ⅲ） window functions,an improved Rife-Vincent Ⅲ windowing algorithm is recommended for the fast acquisition based on PMF-FFT.
文摘基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提出基于函数波束形成的改进FFT-FISTA算法。改进算法以函数波束形成输出作为FFT-FISTA算法的迭代输入,建立函数波束形成、声源分布及升幂空间转移不变点扩散函数的线性方程组,基于周期边界条件下的快速傅里叶变换进行迭代求解,使被运算的非周期函数变为一个周期函数,解决补零边界带来的波数泄漏问题,可提高运算准确性,进一步提升成像性能;通过指数运算锐化点扩散函数主瓣,拓展点扩散函数空间转移不变性假设的适用性。仿真和试验结果表明,相较于常规FFT-FISTA算法,改进算法能提升成像空间分辨率及动态范围,扩大FFT-FISTA算法的有效成像区域,压缩气体泄漏试验结果验证了改进算法的有效性。
