Frequency Response of FIR Filters

Moving Average Filtering• Given the cascade frequency response we can easily convertback to the impulse response of the cascade difference equationhn = n + 3n – 1+ 3n – 2 + n – 3andyn = xn + 3xn–1 + 3xn–2 + xn – 3• Check h 1n*h 2nMoving Average Filtering• The moving average filter occurs frequency enough that weshould consider finding a general expression for the frequencyresponse• The difference equation for an L-point averager isyn • The frequency response is=L – 11-- xn – kL k = 0(6.30)He jˆ=L – 11 –-- e jˆ kL k = 0(6.31)ECE 2610 Signals and Systems 6–24