In FM noise is low as compared to AM.
The AM signal covers more distance than FM signal that's why it gets more distorted.How ever the information in AM signal does not lose but the noise effects it more than that of FM signal,so we get signal with more noise than that of FM signal
For FM
Carson's rule
Main article: Carson bandwidth rule
A rule of thumb, Carson's rule states that nearly all (~98%) of the power of a frequency-modulated signal lies within a bandwidth of
where , as defined above, is the peak deviation of the instantaneous frequency from the center carrier frequency .
Noise quieting
The noise power decreases as the signal power increases; therefore the SNR goes up significantly.
Thanks,
By tauseef ahmed
A: AM radio is an Amplitude Modulation transmission . Meaning it has fix frequency but it is modulated by the signal. FM Frequency Modulation the frequency is modulated by the signal
The difference between frequency modulation and phase modulation is that with frequency modulation the angular frequency of the signal is modified while with the phase modulation, the phase angle of the signal is modified.
There are two types of modulations. They are amplitude modulation and frequency modulation. In AM, amplitude of the signal is modified. In FM, frequency is getting modulated. Frequency modulated with carrier waves are transmitted and received by receivers without any distortion.
AM means Amplitude(=height) modulation, so the frequency stays the same and the message is coded into variations of the strength of the signal. FM stands for Frequency modulation. Here the strength of the signal stays the same and the message is coded into changes in frequency instead.
AM means Amplitude(=height) modulation, so the frequency stays the same and the message is coded into variations of the strength of the signal. FM stands for Frequency modulation. Here the strength of the signal stays the same and the message is coded into changes in frequency instead.
A: A carrier carry information by modulation either Amplitude or Frequency modulation. Therefore AM and FM RADIO M stand for modulation
Both AM (amplitude modulation) and FM (frequency modulation) are methods to add information to a carrier wave. The main difference is how they encode this information: AM varies the signal's amplitude, while FM varies the signal's frequency. AM is more susceptible to interference but has a longer range, while FM is less prone to interference and offers better sound quality.
Not sure what type of modulation you are looking for, but there are two that can be manipulated, either individually or in conjunction:Frequency modulation index refers to the relation between the sine wave frequency (sine_freq) and the triangle (or saw-tooth) wave frequency (triang_freq).The frequency modulation index is equal to ((triang_freq)/(sine_freq)).Amplitude modulation index refers to the relation between the sine wave amplitude (sine_amp) and the triangle (or saw-tooth) wave amplitude (triang_amp).The amplitude modulation index is equal to ((sine_amp)/(triang_amp)).Varying the modulation index (normally by varying the frequency or amplitude of the triangle wave form) changes that respective modulation index.From personal experience, an appropriate amplitude modulation index for an SPWM waveform should be around 0.8(that is, if the triangle has an amplitude of 10, the sine would have an amplitude of 8). This index should never be equal to 1 (one); it should always be less. A.K.A.: the triangle-wave amplitude should always be greater than the sine-wave.On the other hand, a triangle-wave frequency much greaterthan the sine-wave frequency makes an SPWM that in turn generates a "cleaner" synthesized sine-wave in the H-bridge you are probably using. Try different freq. modulation indexes, but an index of at least 10 should be used (preferably somewhere around 100 if you want a good SPWM). That is, if the sine-wave frequency is 60 Hz, the triangle-wave frequency should be above 600, preferably 6,000 or more. Complications in the filter design in the "output" of the H-bridge will vary greatly when playing around with the frequency modulation index. That being said, keeping the amplitude modulation index at a static 0.8, and playing around with the triangle-wave frequency should be your best bet.
so...saying about acoustic waves for e.?amplitude influences loudness and frequency - pitch of tone
In modulation u r sending two signals but their frequencies are sum or difference of carrier frequency and signal frequency.In addition u send two signals at two different frequencies so more interference.
John N. Morrissey has written: 'A comparison between frequency modulation and amplitude modulation for a distance measuring equipment' -- subject(s): Electronics
fc>2fm