Questions tagged [frequency-modulation]

The tag has no usage guidance.

0
votes
1answer
42 views

Noise floor of a FM duplex

If these 2 signals, that form this duplex, have ranges of 15-30 [kHz] and 30-45 [kHz] using: $NoiseFloor_{dBm} =10\log _{10}(k\times T_{0}\times 1000)+NF+10\log _{10}(BW)$ (formula from wikipedia) ...
1
vote
1answer
264 views

Biquad cookbook formula for broadcast FM de-emphasis?

Can a simple IIR biquad filter be used as an audio de-emphasis filter for broadcast FM radio? If so, how does one translate the filter requirements (50 uS time constant in the U.S.?) into parameters ...
0
votes
1answer
47 views

Please help me understand this FM carrier frequency inequality

The link of the statement is evidenced in this book: I don't understand how equation 85 come? I try to use Carson rule to see this inequality but turns out I have $2 \Delta f$ instead of $3 \Delta f$....
3
votes
2answers
5k 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
vote
2answers
2k views

Quadrature modulation for FM and AM

This might be a naïve question, are these correct statements? Both amplitude and frequency modulated radio signals nowadays use quadrature modulation and demodulation as a mean to transfer and ...
0
votes
1answer
120 views

Receiving frequency modulated signal

I have two questions: If the FM radio at the receiver mixes with a another frequency to bring down the carrier frequency, wouldn't that affect the message signal? In today's digital world, why the ...
1
vote
1answer
603 views

How to express FM and PM the most simple way?

I'm trying to understand how to tell phase modulation from frequency modulation by looking at their respective expressions, simplified, particularly frequency modulation. Also, it would be nice for ...
1
vote
1answer
307 views

Simplified equations for FM (frequency modulation) synthesis and PM (phase modulation)?

Clicking on the links I find on the web it seems many authors don't express them neatly enough for me or they're even confusing the two. Can someone please clear this up? Is frequency modulation \...
2
votes
1answer
138 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 ...
0
votes
1answer
387 views

Solving for frequency deviation, $\Delta f $ (FM modulation)

I'm sorry if I posted this in the wrong section. I solved the question and got $50\textrm{kHz}$, but the solution says it is $100\textrm{kHz}$ without any proof. Im asking for someone to tell me ...
1
vote
0answers
131 views

Calculating amplitudes of FM Sidebands

How are the amplitudes of FM sidebands calculated? E.g. when negative frequencies are reflected back and their amplitudes added to any existing positive frequencies at that band, how are the ...
0
votes
0answers
44 views

How to calculate the frequency of the analog information signal? [FM] [duplicate]

How to calculate the frequency of the information signal from the follow spectrum diagram (it contains only one frequency)? Information signal is also called as original signal but i'm not sure.