The receiver in
information theory
Information theory is the mathematical study of the quantification (science), quantification, Data storage, storage, and telecommunications, communication of information. The field was established and formalized by Claude Shannon in the 1940s, ...
is the receiving end of a
communication channel
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for infor ...
. It receives
decoded
message
A message is a unit of communication that conveys information from a sender to a receiver. It can be transmitted through various forms, such as spoken or written words, signals, or electronic data, and can range from simple instructions to co ...
s/
information
Information is an Abstraction, abstract concept that refers to something which has the power Communication, to inform. At the most fundamental level, it pertains to the Interpretation (philosophy), interpretation (perhaps Interpretation (log ...
from the sender, who first
encoded them.
Sometimes the receiver is modeled so as to include the decoder. Real-world receivers like
radio receivers or
telephone
A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...
s can not be expected to receive as much information as predicted by the
noisy channel coding theorem.
Real-world receivers include:
* For modulated radio waves, a
radio receiver
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. ...
** For converting specifically AM modulated radio waves to sound, an
AM Tuner
** For converting specifically FM modulated radio waves to sound, an
FM Tuner
** For converting specifically television transmissions to video and audio, a
television tuner, which may be a component of an
AV receiver
* For modulated ultrasound waves, a
receiver (modulated ultrasound)
* For converting analog electrical signals on a wire to audio, a
speaker system, which may be a component of an
audio headset or telephone
handset.
* For reading magnetic patterns on tape, a
tape head
* For reading magnetic patterns on a disk platter, the read head located on the
disk read-and-write head
A disk read-and-write head is the small part of a disk drive that moves above the disk platter and transforms the platter's magnetic field into electric current (reads the disk) or, vice versa, transforms electric current into magnetic field ...
* For reading printed barcodes, a
barcode reader
A barcode reader or barcode scanner is an optical scanner that can read printed barcodes and send the data they contain to computer. Like a flatbed scanner, it consists of a light source, a lens, and a light sensor for translating optical impul ...
.
References
{{Authority control
Information theory