impulse Response.IIR Filter 000200040.006 0.012 Impulse Response- FIR Filter FIGURE 21.7 Poles/Zeros for lIA Filter Real part FIGURE 21. 8 21.4 Example 3: Multirate Signal Processing Given a signal that has been collected or computed using a process that eliminates or minimizes aliasing from components above the Nyquist frequency (one-half the sampling frequency), we have a great deal of flexibility in modifying the sampling rate. For example, if the frequency content of the signal is much lower than the Nyquist frequency, then the sampling rate can be reduced without losing any of the signal content. This ecimation"process allows us to compress the signal into a form that requires less memory requirements. Ar interpolation"process can be used to interpolate new data points between points of the decimated signal such a way that the frequency content of the new signal is essentially the same as the original signal. The decimation process requires a reduction of data points by an integer factor, M, such as a factor of 3. The c 2000 by CRC Press LLC© 2000 by CRC Press LLC 21.4 Example 3: Multirate Signal Processing Given a signal that has been collected or computed using a process that eliminates or minimizes aliasing from components above the Nyquist frequency (one-half the sampling frequency), we have a great deal of flexibility in modifying the sampling rate. For example, if the frequency content of the signal is much lower than the Nyquist frequency, then the sampling rate can be reduced without losing any of the signal content. This “decimation” process allows us to compress the signal into a form that requires less memory requirements. An “interpolation” process can be used to interpolate new data points between points of the decimated signal in such a way that the frequency content of the new signal is essentially the same as the original signal. The decimation process requires a reduction of data points by an integer factor, M, such as a factor of 3. The FIGURE 21.7 FIGURE 21.8