时域采样与恢复若连续时间信号取频率为200Hz～300Hz的正弦波,计算其有效的频带宽度.该信号经频率为fs的周期脉冲抽样后,若希望通过低通滤波后的信号失真较小,则抽样频率和低通滤波器的截

时域采样与恢复
若连续时间信号取频率为200Hz～300Hz的正弦波,计算其有效的频带宽度.该信号经频率为fs的周期脉冲抽样后,若希望通过低通滤波后的信号失真较小,则抽样频率和低通滤波器的截止频率应取多大,试设计一满足上述要求的低通滤波器.

带宽B：300-200=100Hz

采样率大于2倍最高频率 需要大于600Hz,这里取1000Hz

打开matlab的滤波器设计工具包

设定滤波器类型为你说的低通滤波器,FIR类型,设定f pass=300Hz,f stop=350Hz.阻带衰减60dB

自动完成滤波器设计

得到一个40阶的滤波器,权系数为

const real64_T B[40] = {

  -0.009989618909284, -0.02029074095165,-0.003658761822981,  0.01191660252522,

  -0.006240071821678,-0.007667007974536,  0.01485339446217,-0.004012265112456,

   -0.01571093256692,  0.02001544874986, 0.002248284375145, -0.02939791710244,

    0.02520172811786,  0.01689416127921, -0.05353521126487,  0.02916133042266,

    0.05668551319652,  -0.1206160212491,  0.03134960555358,   0.5345021687799,

     0.5345021687799,  0.03134960555358,  -0.1206160212491,  0.05668551319652,

    0.02916133042266, -0.05353521126487,  0.01689416127921,  0.02520172811786,

   -0.02939791710244, 0.002248284375145,  0.02001544874986, -0.01571093256692,

  -0.004012265112456,  0.01485339446217,-0.007667007974536,-0.006240071821678,

    0.01191660252522,-0.003658761822981, -0.02029074095165,-0.009989618909284

};