This method directly makes quadrature demodulation of the IF signal by utilizing the second-order sampling and sign-alternating,and then calculates the correlation value between the receiver signal and the local spreading code in analog domain.

• 该捕获方法采用二阶采样和符号交替实现中频信号的正交分解；再利用模拟匹配滤波器在模拟域计算接收信号与本地扩频码的相关值.