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Mobile communication is the transfer of data (text, audio, video) between two points without any physical contact by the transmission of electromagnetic waves.
Note: Note: Sometimes we assume that when we talk about mobile communication it is only 'cellular mobile communication' which is wrong. Cellular mobile communication is part of mobile communication, as per the first line of this article, all communication where data is transmitted in the form of electromagnetic waves can be called mobile communication.
In the real world, we have seen many types of mobile communication like WLAN, Bluetooth, and cellular mobile communication(Sim Card based ) but before talking about them we have to understand the basics of mobile communication.
Basic mobile communication
What is basic is that an electromagnetic wave generated from messages like a voice can not travel from one place to another due to low frequency (Frequency approx=20Htz) so the message signal is mixed with a high amplitude wave or high-frequency wave called a carrier wave, then it is transmitted with the help of a transmitter. At the endpoint, the message is separated from the carrier with the help of the receiver
Modulation: The mixing of message signal and carrier wave is called modulation
Following Modulation, techniques are used in the modulation
Before understanding the different types of modulation we need to understand some of the topography which is often used in explaining mobile communication.
signal: It is the electrical representation of a message (data) like audio, video, and text i.e. holds some information. In mobile communication, we refer to a signal as an information signal or a message signal.
Mathematical representation of Signal: Since the electromagnetic wave of a signal is transient in nature (varies with time and repeats itself after one cycle) it is presented with a sine wave.
Vm(t)=Vm sin(2 pi fm t ) (pi=7.14 )
Vm(t)= Voltage of message signal.
Vm= maximum value of the amplitude
fm=Frequency of message signal (no. of oscillation in one second)
Carrier signal: A signal that is mixed with a message signal to propagate in the air. This is a high-frequency wave that carries the information signal to the endpoint
Vc(t)=Vc sin(2 pi fc t)
Vc= maximum value of the amplitude
fc=Frequency of a carrier signal
Channel: It is a medium and path through which the modulated carrier wave propagates and reaches the end-point. in mobile communication air and space serves as channel
Communication using mobile phones called mobile communication.
