Question

The system represented by the following direct form structure is:

(a) General second order system

(b) Purely recursive system

(c) Partial recursive system

(d) FIR system

The question was asked during an online interview.

The origin of the question is Implementation of Discrete Time Systems in section Discrete Time Signals and Systems of Digital Signal Processing

Answer 1

Right choice is (d) FIR system

To explain: The output of the system according to the direct form given is

y(n)= b0x(n)+b1x(n-1)+b2x(n-2)

Since the output of the system is purely dependent on the present and past values of the input, the system is called as FIR system.