10+ Signal Processing Interview Questions and Answers

It is better to take another random shot.

• The probability of hitting the target is higher when taking another random shot.

• Taking the next slot after the one that missed you does not increase the chances of hitting the target.

• Each slot has an equal probability of being chosen, so the odds are the same for both options.

Yes, the resultant wave will be periodic with a period equal to the least common multiple of the two frequencies.

• The period of the resultant wave is determined by the least common multiple of the two frequencies.

• If the frequencies are incommensurable, the resultant wave will not be periodic.

• If the frequencies are harmonically related, the resultant wave will have a period equal to the fundamental period of the lower frequency.

• The amplitude and phase of the resultant wave will...read more

Sampling a sine wave at 1.5 times its original frequency retains the original wave.

• The original wave can be reconstructed using interpolation techniques.

• The Nyquist-Shannon sampling theorem states that a signal can be perfectly reconstructed if it is sampled at twice its highest frequency component.

• Sampling at 1.5 times the original frequency satisfies the Nyquist-Shannon sampling theorem.

• This technique is used in digital audio processing.

The question asks to implement a block diagram for a given transfer function in the form of a/b.

• Identify the numerator and denominator polynomials of the transfer function

• Draw blocks for each polynomial term, representing multiplication and addition operations

• Connect the blocks according to the transfer function equation

• Include any necessary delays or feedback loops

• Label the inputs and outputs of the block diagram

Odd harmonics represent asymmetry in a signal while even harmonics represent symmetry.

• Odd harmonics are multiples of the fundamental frequency and have a phase shift of 90 degrees.

• Even harmonics are also multiples of the fundamental frequency but have a phase shift of 0 degrees.

• Odd harmonics represent the asymmetry in a signal, while even harmonics represent the symmetry.

• For example, a square wave has odd harmonics only, while a triangle wave has both odd and even harmonics.

Z^(-1) represents a unit delay in discrete-time systems, shifting the signal back by one sample.

• Z^(-1) is the z-transform representation of a delay operator.

• It shifts the input signal x[n] to x[n-1], introducing a one-sample delay.

• In digital filters, Z^(-1) is used to implement feedback and feedforward paths.

• Example: If x[n] = {1, 2, 3}, then Z^(-1)x[n] = {0, 1, 2}.

DTFT is a continuous function that represents the frequency content of a discrete-time signal, while DFT is a discrete function that represents the frequency content of a finite-length sequence.

• DTFT is defined for both finite and infinite-length signals, while DFT is only defined for finite-length sequences.

• DTFT is a continuous function in frequency domain, while DFT is a discrete function in frequency domain.

• DTFT provides a complete representation of the frequency content of...read more

No

• The system is not stable because the transfer function has a pole at z = 1

• A stable system should have all poles inside the unit circle in the z-plane

• In this case, the pole at z = 1 lies on the unit circle, making the system marginally stable

IIR and FIR filters are two types of digital filters used in signal processing.

• IIR (Infinite Impulse Response) filters use feedback to create a response to an input signal.

• FIR (Finite Impulse Response) filters only use feedforward and have a finite duration of response.

• IIR filters can be implemented with fewer coefficients but may be less stable than FIR filters.

• FIR filters have linear phase response and are generally more stable than IIR filters.

• Example of IIR filter: Butter...read more

The output sequence y[n] can be obtained by convolving the input sequence x[n] with the impulse response h[n] = [1, 0, 0, 0, -1].

• The given transfer function H(Z) represents a discrete-time system with a finite impulse response (FIR) filter.

• To find y[n], we need to convolve x[n] with the impulse response h[n] = [1, 0, 0, 0, -1].

• Convolution can be performed by sliding the impulse response over the input sequence and summing the products of corresponding samples.

• The resulting se...read more