In
telecommunications
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...
, a ternary signal is a
signal
A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology.
In ...
that can assume, at any given instant, one of three states or
significant conditions, such as
power level,
phase position,
pulse duration, or
frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...
.
Examples of ternary signals are (a) a pulse that can have a positive, zero, or negative voltage value at any given instant (
PAM-3), (b) a sine wave that can assume phases of 0°, 120°, or 240° relative to a
clock
A clock or chronometer is a device that measures and displays time. The clock is one of the oldest Invention, human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, a ...
pulse (3-
PSK), and (c) a
carrier signal
In telecommunications, a carrier wave, carrier signal, or just carrier, is a periodic waveform (usually sinusoidal) that conveys information through a process called ''modulation''. One or more of the wave's properties, such as amplitude or frequ ...
that can assume any one of three different frequencies depending on three different
modulation
Signal modulation is the process of varying one or more properties of a periodic waveform in electronics and telecommunication for the purpose of transmitting information.
The process encodes information in form of the modulation or message ...
signal significant conditions (3-
FM).
Some examples of PAM-3
line code
In telecommunications, a line code is a pattern of voltage, current, or photons used to represent digital data transmission (telecommunications), transmitted down a communication channel or written to a storage medium. This repertoire of signal ...
s that use ternary signals are:
*
hybrid ternary code
*
bipolar encoding
*
MLT-3 encoding used in
100BASE-TX Ethernet
*
B3ZS
*
4B3T used in some ISDN
basic rate interface
*
8B6T used in
100BASE-T4 Ethernet
*
return-to-zero
*
SOQPSK-TG uses ternary continuous phase modulation
3-PSK can be seen as falling between "binary phase-shift keying" (
BPSK), which uses two phases, and "quadrature phase-shift keying" (
QPSK), which uses four phases.
References
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See also
*
Balanced ternary
Balanced ternary is a ternary numeral system (i.e. base 3 with three Numerical digit, digits) that uses a balanced signed-digit representation of the integers in which the digits have the values −1, 0, and 1. This stands in contrast to the stand ...
*
Digital signal (electronics)
A digital signal is a signal that represents data as a sequence of discrete space, discrete values; at any given time it can only take on, at most, one of a finite number of values. This contrasts with an analog signal, which represents contin ...
*
Fast Ethernet#100BASE-T2 uses PAM-5, which, like ternary, is one of the few modulation schemes that does not use a power-of-two number of symbols.
*
Ternary computer
*
Three-phase electric power
Three-phase electric power (abbreviated 3ϕ) is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional n ...
, like 3-PSK, uses 3 phases at a single frequency and amplitude.
*
Three-valued logic
In logic, a three-valued logic (also trinary logic, trivalent, ternary, or trilean, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating ''true'', ''false'', and some third value ...
Line codes
Ternary computers
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