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In telecommunications and electronics, baud (pronounced /bɔːd/ unit symbol "Bd"), is a measure of the symbol rate; that is, the number of distinct symbol changes (signalling events) made to the transmission medium per second in a digitally modulated signal. The baud is named after Emile Baudot, the inventor of the Baudot code for telegraphy. Baud is a small town located in the Morbihan county of Brittany, France. ...
Telecommunication involves the transmission of signals over a distance for the purpose of communication. ...
Electronics is the study of the flow of charge through various materials and devices such as, semiconductors, resistors, inductors, capacitors, nano-structures, and vacuum tubes. ...
In digital communications, the symbol rate is the bit rate divided by the number of bits transmitted in each symbol. ...
Look up second in Wiktionary, the free dictionary. ...
In telecommunications, modulation is the process of varying a periodic waveform, i. ...
Émile Baudot, (September 11, 1845 - March 28, 1903), French telegraph engineer and inventor of the Baudot code. ...
The Baudot code, named after its inventor Émile Baudot, is a character set predating EBCDIC and ASCII and used originally and primarily on teleprinters. ...
Optical Telegraf of Claude Chappe on the Litermont near Nalbach, Germany Telegraphy (from the Greek words tele (τηλε) = far and graphein (γÏαφειν) = write) is the long-distance transmission of written messages without physical transport of letters, originally by changing something that could be observed from a distance (optical telegraphy). ...
Since the term is derived from a person's last name, by international standard it is capitalized as Bd in abbreviations, in the same way the decibel (dB) is capitalized in deference to Alexander Graham Bell, and similarly not capitalized when the name of the unit rather than the abbreviation is given. Alexander Graham Bell (3 March 1847 – 2 August 1922) was a Scottish scientist, inventor, and innovator. ...
Although the term “baud rate” is commonly used to refer to the bit rate, this usage is incorrect. See below.
Bit rate per baud
The baud (symbol rate) is distinct from the bit rate, because one symbol may carry more than one bit of information. For example, in voiceband modems, where spectral efficiency is important, it is commonly arranged for one symbol to carry 3 or more bits. Thus a 3000-bit per second modem, which is transmitting symbols that each carry 3 bits, should be described as operating at 1000 baud. Conversely, direct-sequence spread spectrum operation requires many symbols to carry only one bit. In telecommunications and computing, bit rate (sometimes written bitrate) is the frequency at which bits are passing a given (physical or metaphorical) point. It is quantified using the bit per second (bit/s) unit. ...
A modem (from modulate and demodulate) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. ...
Spectral efficiency or spectrum efficiency refers to the amount of information that can be transmitted over a given bandwidth in a specific digital communication system. ...
In telecommunications, direct-sequence spread spectrum (DSSS) is a modulation technique. ...
Unfortunately, this distinction is not widely understood. Early modems operated only at one bit per symbol, and so baud and bit rate for those devices were equivalent. This has led many to believe the two terms to be synonymous, which they are not.
Conveying more than one bit per symbol has advantages. This reduces the time required to send a given quantity of data, and allows modern modems, FDDI and 100/1000 Mbit/s Ethernet LANs, and so on, to achieve high data rates. An optimal symbol set design must take into account channel bandwidth, desired information rate, noise characteristics of the channel and the receiver, and receiver and decoder complexity. A typical 2400-bit/s modem actually transmits at 600 baud (600 symbol/s), where each quadrature amplitude modulation symbol carries four bits of information. And further, 1000 Mbit/s Ethernet LAN cables use multiple wire pairs and multiple bits per symbol to encode their data payloads. Specifically, 1000BASE-T uses 4 wire pairs and 2 data bits per symbol to get a symbol rate of 125MBd. In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ...
A modem (from modulate and demodulate) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. ...
Quadrature amplitude modulation (QAM) is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. ...
A bundle of optical fiber. ...
Ethernet is a large, diverse family of frame-based computer networking technologies that operates at many speeds for local area networks (LANs). ...
1000BASE-T or IEEE 802. ...
Conversely, representing one bit by many symbols has the advantage of overcoming signal noise, particularly radio jamming, hence is commonplace in military radio and in CDMA radio including cell phones, despite the disadvantage of using more bandwidth to carry the same bit rate. In these systems each signal is called a "chip" and the baud is also known as the chip rate. In science, and especially in physics and telecommunication, noise is fluctuations in and the addition of external factors to the stream of target information (signal) being received at a detector. ...
Radio jamming is the (usually deliberate) transmission of radio signals that disrupt communications by decreasing the signal to noise ratio. ...
In telecommunication, a combat-net radio (CNR) is a radio operating in a network that (a) provides a half-duplex circuit and (b) uses either a single radio frequency or a discrete set of radio frequencies when in a frequency hopping mode. ...
General Information Generically (as a multiplexing scheme), code division multiple access (CDMA) is any use of any form of spread spectrum by multiple transmitters to send to the same receiver on the same frequency channel at the same time without harmful interference. ...
Several mobile phones A mobile telephone or cellular telephone (commonly mobile phone or cell phone) is a long-range, portable electronic device used for mobile communication. ...
This article does not cite any references or sources. ...
A clear example of the difference between baud (or signalling rate) and the data rate (or bit rate) is a man using a single semaphore flag. He can move his arm to a new position once each second, so his signalling rate (baud) is 1 symbol per second. However, the flag can be held in one of eight distinct positions: Straight up, 45 degrees left, 90 degrees left, 135 degrees left, straight down (which is the rest state, where he is sending no signal), 135 degrees right, 90 degrees right, and 45 degrees right. This means each signal carries three bits of information, as it takes 3 binary digits to encode 8 distinct states – so the data rate is 3 bits per second. In the Navy, more than one flag pattern and arm can be used at once, so the combinations of these produce many symbols, each conveying several bits, thus a higher data rate. A Chappe semaphore tower near Saverne, France // The semaphore or optical telegraph is an apparatus for conveying information by means of visual signals, with towers with pivoting blades or paddles, shutters, in a matrix, or hand-held flags etc. ...
The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ...
See also A modem (from modulate and demodulate) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. ...
This article does not cite any references or sources. ...
In telecommunications and computing, bitrate (sometimes written bit rate, data rate or as a variable Rbit) is the number of bits that are conveyed or processed per unit of time. ...
This is a list of device bandwidths: the channel capacity (or, more informally, bandwidth) of some computer devices employing methods of data transport is listed by bit/s, kilobit/s (kbit/s), megabit/s (Mbit/s), or gigabit/s (Gbit/s) as appropriate and also MB/s or megabytes per...
PCM is an initialism which can have different meanings: Phase Change Material Pulse-code modulation, a way to digitally encode signals representing sound and their video counterparts Potential Cancer Marker Communist Party of Mexico Plug Compatible Manufacturer Power-train control module, a computer in a car which controls the car...
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