Sequentially Adapted Parallel Feedforward Active Noise Control of Noisy Sinusoidal Signals

Figure 3

The optimum filter 𝑊^∘_𝜈(𝜔) for the random noise can be way-off when compared to 𝑊₀(𝜔), that is, 𝑊^∘_𝜈(𝜔_𝑘)≠𝑊₀(𝜔_𝑘). The dashed circled regions show frequencies where 𝑊^∘_𝜈(𝜔) deviates considerably from 𝑊₀(𝜔). Presence of tones in these regions will affect the performance of single-filter ANC methods.