Communication systems
Communication is the basic process of exchanging information. The basic components of an electronic communication system are:
1) Transmitter.
2) Communication channel.
3) Receiver.
A Transmitter is a collection of electronic circuits designed to convert the information into a signal suitable for transmission over a given communication medium. A Receiver is a collection of electronic circuits designed to convert the signal back to the original information. The Communication channel is the medium by which the electronic signal is transmitted from one place to another.
A radio communication system sends signals by radio. Types of radio communication systems deployed depend on technology, standards, regulations, radio spectrum allocation, user requirements, service positioning, etc. The radio equipment involved in communication systems includes a transmitter and a receiver, each having an antenna and appropriate terminal equipment such as a microphone at the transmitter and a loudspeaker at the receiver in the case of a voice-communication system.
The power consumed in a transmitting station varies depending on the distance of communication and the transmission conditions. The power received at the receiving station is usually only a tiny fraction of the transmitter's output, since communication depends on receiving the information, not the energy that was transmitted.
Classical radio communications systems use frequency-division multiplexing (FDM) as a strategy to split up and share the available radio-frequency bandwidth for use by different parties communications concurrently. Modern radio communication systems include those that divide a radio-frequency band by time-division multiplexing (TDM) and code-division multiplexing (CDM) as alternatives to the classical FDM strategy. These systems offer different tradeoffs in supporting multiple users, beyond the FDM strategy that was ideal for broadcast radio but less so for applications such as mobile telephony.
A radio communication system may send information only one way. For example, in broadcasting a single transmitter sends signals to many receivers. Two stations may take turns sending and receiving, using a single radio frequency; this is called "simplex." By using two radio frequencies, two stations may continuously and concurrently send and receive signals - this is called "duplex" operation.
Do the following tasks:
1) Translate into Russian.
2) Write a summary.
What is Modulation?
Modulation is the process of superimposing the information contents of a modulating signal on a carrier signal (which is of high frequency) by varying the characteristics of carrier signal according to the modulating signal.
Modulation is a process in which the base band signal modifies another high-frequency signal called the carrier.
Types of Modulation
We can modulate the information-bearing signal into two types namely.These
are called Modulation Techniques.
Analog Modulation
Digital Modulation
Analog modulation is the process of converting an analog input signal into a
signal that is suitable for RF transmission.
Digital modulation is the process of converting a digital bistream into an analog signal suitable for RF transmission.