Question

1. from implementation perspective, FIR filters ____________________
   1. require iterative structure
   2. can be more difficult of implement
   3. require memory
   4. require non-causal impulse response

2. An ideal LPF impulse response usually converted to practical filter by
   1. applying rectangular window
   2. applying rectangular window and shifting impulse response to right by half samples
   3. applying hamming window
   4. capturing 90% or more impulse response signal energy