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ecestar
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what is the meaning of modulation and what is types
can anyone explain that to me
and give me any book.
can anyone explain that to me
and give me any book.
at first i want to now what is the fm modulation and the am modulation and what is the difference between both and how can i choose the type of the modulationJoAuSc said:You need to give us a lot more information before we can tell what you're asking for. Where did you hear about "modulation"? Is it in reference to "amplitude modulation" or "frequency modulation", both of which describe ways information is encoded in radio waves?
JoAuSc said:Let's say the signal we want to transmit is [tex]s(t)[/tex]. AM modulation is the following:
[tex]s(t) A \sin(\omega t)[/tex]
Here [tex]\sin(\omega t)[/tex] is the carrier signal, [tex]\omega[/tex] is its angular frequency, [tex]A[/tex] is a constant, and [tex]t[/tex] is time.
FM modulation is the following:
[tex]A \sin(B s(t) t)[/tex]
[tex]B[/tex] is a constant, and the other variables are the same as they were above.
I don't know the specifics of how these are used in radio.
Modulation is the process of changing or varying a carrier signal in order to transmit information. It is important because it allows us to send and receive information over long distances, and is used in various communication systems such as radio, television, and internet.
The main types of modulation are amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM). There are also variations of these, such as double sideband modulation (DSB) and quadrature amplitude modulation (QAM).
In AM, the amplitude or strength of the carrier signal is varied in proportion to the amplitude of the modulating signal. This creates sidebands around the carrier frequency, which contain the transmitted information. The receiver then demodulates the signal to extract the original information.
In FM, the frequency of the carrier signal is varied in proportion to the amplitude of the modulating signal. In PM, the phase of the carrier signal is varied instead. FM is more commonly used in communication systems, while PM is often used in radar and satellite communication.
The modulation index is a measure of the amount of modulation present in a signal. It is typically calculated as the ratio of the peak deviation of the carrier signal to the frequency or amplitude of the modulating signal. A higher modulation index means a stronger modulation and more information can be transmitted, but too high of a modulation index can cause distortion in the signal.