Test on Fundamentals of Digital Signal Processing Systems

Question 1: The verification process shown for Example #1 confirms that the signal flow diagram correctly implements the unit impulse response g[n] where g[0] = 0, g[1] = 1, g[2] = 2, and g[n] = 0 otherwise.

A. Ano

B. Ne

Explanation: The 'Example #1 – Signal Flow Verification' section systematically checks the output y[n] for various n values (n < 0, n = 0, n = 1, n = 2, n > 2) against the given impulse response g[n], concluding with 'verified g n'.

Question 2: In a Signal Flow Diagram for a Linear Time Invariant (LTI) system, what is the function of the block labeled 'Multiplication by a constant'?

A. It introduces a time delay to the input signal.

B. It sums the input signal with a constant value.

C. It multiplies the input signal by a specified constant value.

D. It calculates the inverse of the input signal and multiplies it by a constant.

Explanation: The study materials explicitly state that the 'Multiplication by a constant' block takes an input x[n] and produces an output y[n] = a * x[n], where 'a' is the constant. This signifies that the block multiplies the input signal by a constant value.

Question 3: A DSP system is considered BIBO stable if a bounded input can result in an unbounded output.

A. Ano

B. Ne

Explanation: A DSP system is BIBO stable if and only if the response for a bounded input is bounded. If a bounded input results in an unbounded output, the system is unstable.

Question 4: The system described in Example #3 remains stable if the constant 'a' is changed to 0.5.

A. Ano

B. Ne

Explanation: The study materials state that the stability condition for the system in Example #3 is |a| < 1. If 'a' is changed to 0.5, then |0.5| < 1, which means the system would be stable, not remain stable given it was unstable with a=2. Therefore, the statement is false.

Question 5: According to the study materials, what is the primary distinction between a Finite Impulse Response (FIR) system and an Infinite Impulse Response (IIR) system?

A. FIR systems have an impulse response that decreases exponentially but never ends, while IIR systems have an impulse response that is limited in time.

B. FIR systems are always stable, whereas IIR systems can be unstable.

C. FIR systems have a unit impulse response that is limited in time (all samples are zeros after a certain point), while IIR systems have a unit impulse response that never completely finishes.

D. FIR systems only process digital signals, while IIR systems can process both analog and digital signals.

Explanation: The study materials state that 'Finite Impulse Response System' (FIR syst.) refers to systems where the unit impulse response is limited in time, meaning all samples are zeros after a certain point. In contrast, 'Infinite Impulse Response System' (IIR syst.) refers to systems where the unit impulse response never completely finishes, even if it exponentially decreases.