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What is modulation spectrum?
We thus have developed such a theory from an engineering perspective and, using terminology from speech research, call the key result of this theory the “modulation spectrum.” A modulation spectrum decomposes a signal into a two-dimensional representation of standard frequency versus frequency of the dynamics.
What is modulated noise?
Noise which is present only in company with a signal. This uncertainty sounds like added noise and is not present if the signal is not present.
Which modulation is more noisy?
Important point: In frequency modulation mf (frequency modulation index) is inversely proportional to modulating frequency fm. While in PM it does not vary with modulating frequency. Moreover, FM is more noise immune.
What is the spectrum of modulated noise signal?
Thew new spectrums will show two sources of energy from -1100Hz to -900Hz and 900Hz to 1100Hz. To answer your question, we also should consider that their source signal is white-noise, and the carrier signal is a square wave rather than a sinusoid.
Modulating with a square wave will create multiple images of your source signal to appear, each centered around the square wave’s harmonics and scaled by the half the strength of the harmonic. If your input signal is true white noise (really only observed mathematically), the shifted noise signals would only add up to more white noise.
How is phase modulated noise represented in an oscillator?
An ideal oscillator would generate a pure sine wave. In the frequency domain, this would be represented as a single pair of Dirac delta functions (positive and negative conjugates) at the oscillator’s frequency; i.e., all the signal’s power is at a single frequency. All real oscillators have phase modulated noise components.
What makes up the spectrum of white noise?
Short answer: most likely white noise. Amplitude modulation using a sinusoidal wave shifts the original spectrum in frequency by the sinusoids frequency.