Question

You are required to design an FIR digital filter for real-time extraction of a signal corrupted by noise. The signal information is in the 0 - 1500 Hz and 8000 -10000 Hz bands, while the noise has most of its energy in the 2000 Hz - 7000 Hz band. What kind of filter should you design for this application?

• A. Bandpass

• B. Lowpass

• C. Highpass

• D. Bandstop  

• For the same problem, what is the transition bandwidth parameter for designing a Kaiser Window-based FIR filter?

• A. 3000

• B. 1000

• C. 500

• D. 2000

Answer 1

1. As per the statement, a specific range of frequency needs to be eliminated to eliminate noise from the signal. So for this application, Bandstop filter is most suitable.

But on the other hand, the signal information lies between two ranges of frequency, for that we can have 2 band pass filter in parallel combination but this combination is not economic so if we have only one bandstop filter, we can easily achieve the condition.

2. The transition bandwidth is 500 as 2000-1500=500