3.4.3 Notch and comb filters To remove periodic artifacts (periodic in the time domain) (discrete in the frequency domain)

3.4.3 Notch and comb filters To remove periodic artifacts (periodic in the time domain) (discrete in the frequency domain) Figure 3.40

DC gain = ?

Figure 3.41

Figure 3.42

Figure 3.43

Figure 3.44

Figure 3.45

3.5 Optimal filtering: the Wiener filter

3.6 Adaptive filters for removal of interference

3.7 filter selection Synchronized averaging: Signal: stationary or cyclo-stationary Signal: Periodic or quasi-periodic Synchronization is possible Noise: stationary, random, uncorrelated with the signal, zero mean

MA averaging: Signal: stationary (over the window duration) Noise: stationary (over the window duration) , zero mean Signal: low-frequency on-line, real-time

Frequency-domain fixed filter: Signal: stationary Noise: stationary signal is band-limited or noise is band-limited

Optimal filter: * Signal: stationary

Adaptive filter: Signal: not necessarily stationary uncorelated between signal and noise No information about the signal and the noise Reference is available

Adaptive filter:

HW

5. N = 2 - 8 Fc = 0.5 – 5