基于带通采样的抗混叠滤波器设计

Anti-aliasing filter design based on bandpass sampling

为解决采样过程中因有用信号混叠导致多频段信号在同一平台上无法正常接收的问题,提出一种基于二阶带通采样的抗混叠滤波算法。多频段带通信号通过可调延时差的二阶带通采样处理,形成两路具有相位差的采样后信号,利用相位差设计抗混叠滤波器,调整两信号相位,使其中一个信号经过叠加后信号为零,而另一信号不变,实现两混叠信号的分离。仿真结果表明,该抗混叠滤波算法可以有效实现两路混叠信号的分离且信号具有较好的重构性能。

To solve the problem that multi-band signals cannot be received normally on the same platform due to aliasing of useful signals during sampling,an anti-aliasing filtering algorithm based on second-order band-pass sampling was proposed.The multi-band bandpass signal was processed by a second-order bandpass sampling process with adjustable delay difference to form two sampled signals with phase difference.The anti-aliasing filter was designed using the phase difference,and the two signal phases were adjusted to make one of the signals pass.After the superposition,the signal was zero and the other signal remained unchanged,thus achieving the separation of the two alias signals.Simulation results show that the anti-aliasing filtering algorithm can effectively separate the two aliased signals and the signal has good reconstruction performance.