公开(公告)号：US07102548B1

公开(公告)日：2006-09-05

申请号：US11219415

申请日：2005-09-02

申请人： Shenq-Huey Wang ,  William D. Elliott ,  Xiemei Meng

发明人： Shenq-Huey Wang ,  William D. Elliott ,  Xiemei Meng

IPC分类号： H03M7/00 ,  G06F17/17

CPC分类号： H03H17/0671 ,  H03H2017/0678

摘要： We disclose a CIC digital filter having an arbitrary-integer decimation rate. The filter has a shifter connected to its input. The shifter receives a shift control input, where the shift control input is pre-computed as equal to the integer portion of 2 raised to the base-2 logarithm of the gain of the CIC filter. There is a multiplier connected between the input and the shifter. In other embodiments, the multiplier could be connected between the input and the shifter. Sequentially-connected integrator functions are connected to the shifter (or multiplier); a decimation function receives input from the integrator functions; and sequentially-connected differentiator functions receive input from the decimation function. The decimation function has a selectable rate equal to any integer between 1 and a number equal to the predetermined maximum decimation value. The multiplier is configured to compute the product of each input data sample by a correction factor; the correction factor being pre-computed as equal to the fractional portion of 2 raised to the base-2 logarithm of the gain of the CIC filter, so as to correct the gain of the CIC filter for decimation values not a power of 2.

摘要翻译： 我们公开了具有任意整数抽取率的CIC数字滤波器。 滤波器具有连接到其输入端的移位器。 移位器接收移位控制输入，其中移位控制输入被预先计算为等于CIC滤波器的增益的基数2对数的2的整数部分。 在输入和移位器之间连接一个乘法器。 在其他实施例中，乘法器可以连接在输入和移位器之间。 顺序连接的积分器功能连接到移位器（或乘法器）; 抽取功能从积分器功能接收输入; 并且顺序连接的微分器功能从抽取功能接收输入。 抽取功能具有等于1和等于预定最大抽取值的数字之间的任何整数的可选择速率。 乘法器被配置为通过校正因子来计算每个输入数据样本的乘积; 校正因子被预先计算为等于2的分数部分提高到CIC滤波器的增益的基数2对数，以便校正CIC滤波器对于不是2的幂的抽取值的增益。