Transferred from: http://baike.baidu.com/link?url= KEOJCOEXYDZUH8N7BNUGEDUTAGLDGDI7ESJUSZESPUREBK0NI6SFMTPWGIRED-H-L3ZZ7CY6QSHXVHHILK7BCQ the speed at which a microcontroller or computer communicates at the serial port. Refers to the signal is modulated after the change in the unit time, that is, the number of times the carrier parameter changes in the unit time, such as 240 characters per second, and each character format contains 10 bits (a starting bit, 1 stop bit, 8 data bits), the baud rate is 240Bd, bit rate is 10 bits * 240/sec = 2400bps. Another example is the transmission of 240 bits per second, when the baud rate is 240Bd, bit rate is also 240bps. (But the general modulation rate is greater than the baud rate, such as Manchester code). Baud rate can be popularly understood as how many yards of data a device sends (or receives) within a second. It is a measure of the symbol transfer rate, 1 baud refers to the transmission of 1 code symbols per second (through different modulation, can load multiple bit bit information on a code element symbol), 1 bits per second refers to the transmission of 1 bits per second (bit). The unit "baud" itself is already representing the number of modulation per second, with "baud per second" (Baud per second) unit is a common error.
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Chinese name
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Baud rate
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Foreign names
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Baud
Rate
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Other names
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code element rate
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Role
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measure symbol transfer rate
Directory
- 1 Concepts
- 2 Analysis Examples
- 3 with Bit rate
ConceptEditThe rate of the analog line signal is measured by the number of oscillations per second of the waveform. If the data is not compressed, the baud rate equals the number of bits transmitted per second, and if the data is compressed, the number of data bits transmitted per second is usually greater than the modulation rate, making the exchange use baud and bits per second occasionally producing errors. In the information transmission channel, the signal unit that carries the data information is called the code element, and the number of code elements transmitted through the channel is called the code element transmission rate, referred to as the baud rate. The baud rate refers to the modulation rate of the data signal to the carrier, which is represented by the number of times the carrier modulation state changes in the unit time (that is, the number of symbols modulated per second), which is the unit baud (BAUD,SYMBOL/S). The baud rate is the indicator of the bandwidth of the transmission channel. The amount of information transmitted through the channel per second is called the bit transfer rate, which is the number of bits transmitted per second, or bit rate. Bit rate indicates the transfer rate of valid data, with B/s, bit/s, bit/sec, read: bits per second. [1] The relationship between baud rate and bit rate can also be converted to: bitrate = baud rate * The number of bits for a single modulation state, for example, assuming a data transfer rate of 120 symbols per second (SYMBOL/S) (that is, the baud rate is 120Baud), and assume that each symbol is 8 bits (bit) is the eight-phase modulation ( A single modulation state corresponds to 3 bits), it transmits a bit rate of (120symbol/s) * (3bit/symbol) =360bps. Analysis ExampleEditIt is a measure of the rate of signal transmission, usually in "baud" (baud) units. The baud rate is sometimes confused with the bit rate, which is actually a measure of the rate of information transmission (messaging rate). The baud rate can be understood as the number of transmission code element symbols per unit of time (rate of transfer of symbols), through different modulation methods can load multiple bits of information on a code element. The baud rate generally refers to the communication speed of the modem. The baud rate refers to the number of times the line status has changed. Only each signal is equal to the number of bits per second when it conforms to one of the transmitted data. In order to communicate with each other, the modem must operate with the same baud rate. If the modem's baud rate is set higher than the baud rate of the other modems, the faster modem usually changes its baud rate to match the slower modem. (Strictly speaking, the baud rate is not in the transmission field, the transmission, channel and other words prone to confusion, the baud rate describes the ability to modulate the signal within a unit of time, the signal is modulated by it in the form of the transmission, or, in this way, the signal in the transmission process, if you want to pass the digital-to-analog conversion, Then the transmission time in addition to consumption in other fields, but also consumed in the modulation process and transmission process in the channel, describing the signal modulation capability with the baud rate, describing the signal transmission capacity with bit rate. ) with bit rateEditBit rate in the digital channel, the bitrate is the transmission rate of the digital signal, which is represented by the number of effective bits (bits) of the binary Code transmitted within a unit of time, expressed in units of bit/s (bps) per second, kilobits per second (Kbps), or megabits per second (Mbps) ( Here K and M are 1000 and 1000000 respectively, instead of 1024 and 1048576 when the computer memory capacity is involved. Baud rate baud rate index according to the signal to the carrier modulation rate, it is in the unit time the carrier modulation state changes the number of times to express, its unit is Porter (Baud). The bit rate has such a relationship with the baud rate: the baud rate is related to the bitrate: bit rate = baud rate x the number of bits corresponding to the individual modulation state. I=S*LOG2 (N) where
IFor the messaging rate,
SIs the baud rate,
NThe amount of information to load for each symbol, in bits. How do you differentiate between them? Obviously, the bit rate of the two-phase modulation (a single modulation state corresponds to 1 bits) is equal to the baud rate, the bit rate of the four-phase modulation (2 bits for a single modulation state) is twice times the baud rate, and the bit rate of the eight-phase modulation (3 bits for a single modulation state) is three times times the baud rate;
Baud rate principle "turn"
