Question

The primary application of the Discrete Fourier Transform in signal processing is:

• A. To convert time-domain signals into their frequency-domain representation
• B. To amplify the signal strength
• C. To reduce noise in the time-domain signal
• D. To convert analog signals to digital form

Hint:

Time to frequency — that's the core job of DFT. Use it to “see” what frequencies make up your signal!

Answer 1

The Correct Option is A

The Discrete Fourier Transform (DFT) is a mathematical technique used in digital signal processing to convert a signal from its original time domain into the frequency domain. This transformation allows engineers and scientists to analyze the frequency components present in a signal, which is essential in applications such as audio processing, communications, and spectral analysis.
The frequency-domain representation provides insight into how different sinusoidal components (frequencies) contribute to the overall signal, making it invaluable for tasks such as filtering, modulation, and spectral estimation.
Why the other options are incorrect:

• (B) Amplification refers to increasing signal strength, which is not a function of the DFT.
• (C) While noise reduction may be performed after transforming to frequency domain, it is not the DFT's primary function.
• (D) Analog-to-digital conversion is done by ADCs, not DFTs.

Hence, the main purpose of DFT is to analyze the signal's frequency content.