Questions tagged [frequency-modulation]

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3
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1answer
353 views

Simulation of a Frequency ramp

This might be an easy one! Please preface your answer with spoiler notation by typing the following two characters first ">!" Given the following equation that describes a cosine wave as a function ...
1
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1answer
979 views

How to generate IQ component for transmitting 2FSK

I am trying to generate IQ components for 2FSK modulation. I have started off from this thread FSK and IQ modulation , but I don't quite understand the IQ TX components plotted in the example there by ...
3
votes
2answers
6k views

FSK and IQ modulation

I am having trouble understanding the FSK modulation process. There are many ways of demodulating the FSK signal. What is the advantage of performing the FSK using IQ modulation? How to demodulate ...
1
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2answers
2k views

IQ FM Demodulation of Wow and Flutter Signal in Software

Background: I have a recording device that exhibits Wow and Flutter, or periodic frequency deviation. I use this device to record a calibrated 3.15kHz test tone from a tape film to generate a .wav ...
2
votes
1answer
275 views

What's the relationship between the parameters of this noise generator and the gaussian curve it produces in the frequency domain?

This algorithm produces a sequence $y$ having a magnitude spectrum that resembles a normal distribution, peaking at frequency $\omega$: $$b[n]=(1-\sigma)b[n-1]+\frac{\sigma}{\omega} C$$ $$p[n]=p[n-1]+...
2
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1answer
2k views

How to convert sampled real audio signal to it's IQ components for IQ modulation?

So my question is this: How to convert sampled real audio signal to it's IQ components for IQ modulation? For instance: WHen I have my DSP or FPGA receive a audio signal through a ADC, which is just ...
1
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1answer
126 views

Frequency response of FM modulation/demodulation chain with phase derivative demodulation

Frequency modulating a carrier by white noise and then demodulating the complex signal using discrete derivative of phase it appears that the discriminator is acting as a low-pass filter. How do I ...
-1
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1answer
160 views

How to generate WBFM from NBFM?

An FM signal is given by $$ s_{FM}(t) = A_c \cos [\omega_C t +k_f \int _{-\infty}^t m(\alpha)d \alpha] $$ Let $ \int _{-\infty}^t m(\alpha)d \alpha] = a(t) $ Therefore, $ s_{FM}(t) = A_c \cos [\...
-2
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1answer
77 views

How to generate WBFM from NBFM

A narrowband FM is approximately given by: $ x(t)= A[\cos w_ct - k_f a(t)\sin w_ct] $ where $ a(t)= \int _{ -\infty } ^t m(\alpha) d\alpha$ How does frequency multiplying $x(t)$ by a desired ...