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Early uses of the term Nyquist frequency, such as those cited above, are all consistent with the definition presented in this article.Some later publications, including some respectable textbooks, call twice the signal bandwidth the Nyquist frequency; [6] [7] this is a distinctly minority usage, and the frequency at twice the signal bandwidth is otherwise commonly referred to as the Nyquist rate.
In telecommunications, an eye pattern, also known as an eye diagram, is an oscilloscope display in which a digital signal from a receiver is repetitively sampled and applied to the vertical input (y-axis), while the data rate is used to trigger the horizontal sweep (x-axis). It is so called because, for several types of coding, the pattern ...
A signal transmitted differentially. Notice the increased amplitude at the receiving end. Differential signalling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor.
An optical communication system is any form of communications system that uses light as the transmission medium. Equipment consists of a transmitter, which encodes a message into an optical signal, a communication channel, which carries the signal to its destination, and a receiver, which reproduces the message from the received optical signal.
A signaling protocol is a type of communications protocol for encapsulating the signaling between communication endpoints and switching systems to establish or terminate a connection and to identify the state of connection. The following is a list of signaling protocols: ALOHA; Digital Subscriber System No. 1 (EDSS1) Dual-tone multi-frequency ...
The Nyquist–Shannon sampling theorem is an essential principle for digital signal processing linking the frequency range of a signal and the sample rate required to avoid a type of distortion called aliasing. The theorem states that the sample rate must be at least twice the bandwidth of the signal to avoid aliasing.
Since each tone (i.e., symbol) represents a message consisting of two digital bits in this example, the bit rate is twice the symbol rate, i.e. 2000 bits per second. According to one definition of digital signal, [3] the modulated signal is a digital signal. According to another definition, the modulation is a form of digital-to-analog conversion.
In a communication system, a transmitter encodes a message to create a signal, which is carried to a receiver by the communication channel. For example, the words " Mary had a little lamb " might be the message spoken into a telephone .