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## Difference between Bit rate and Baud rate | Bit rate vs Baud rate

This page compares Bit rate vs Baud rate and mentions difference between Bit rate and Baud rate used in data communication with examples.

Introduction: In data communication, digital data refers to information in the form of text, numbers, images, audio, video etc. These digital data are stored in the form of bits (i.e. ones and zeros). It is also known as binary data due to its smallest entity used to represent information.

There is another parameter known as signal elements which is used to map data elements to make them suitable for transmission over the channel. Line coding techniques such as unipolar, polar and bipolar are used to convert bits to digital signal.

The ratio ('r') defines number of data elements carried by each signal element.
For examples (As shown in the figure) ,
One data element is mapped per two signal elements than 'r' equals 1/2.
Two data elements are mapped per one signal element than 'r' equals 2/1 i.e. 2. For example QPSK
Similarly four binary bits are mapped using one symbol in 16QAM modulation scheme. The figure depicts data elements and their signal elements representation as described above.

### Bit Rate

• The data rate or bit rate defines number of data elements (i.e. bits) transmitted in one second.
• The unit of bit rate is bits per second or bps or bits/sec.
• It can also be represented in kbps (Kilo bits per second) or Mbps (Mega bits per second).
• The bit rate or data rate of the digital system should be high so that users can experience higher speed of transmission. ### Baud Rate

• The signal rate or baud rate defines number of signal elements transmitted in one second.
• The unit is baud.
• It is also known as pulse rate or modulation rate or symbol rate.
• The signal rate of the digital system should be low which helps in conserving bandwidth usage. This makes system bandwidth efficient.

The relationship between bit rate and baud rate is expressed in the above formula or expression.

Example #1 : AM modulation, Each signal element carry one binary data, Hence r =1
S (Symbol rate or Baud rate) = N (Bit Rate)
Example #2 : 16-QAM modulation, 4 bits are represented by one symbol or signal. Hence r = 4
S = N/4 i.e. bit rate (N) is four times Symbol rate or Signal rate or Baud rate

### Tabular difference between bit rate and baud rate

Following table mentions difference between bit rate and baud rate with respect to various parameters.

Parameters Bit Rate Baud Rate
• Definition Transmission of number of binary bits per sec is known as bit rate. Transmission of number of signal elements or symbols per sec is known as baud rate.
• Unit bps, kbps, Mbps, Gbps Baud, Kbaud, Mbaud
• Formula Bit rate = Baud rate x Number of bits per baud Baud rate = bit rate/ Number of bits per baud
• Relationship in data communication Higher bit rate improves speed of data transmission. Lower signal rate (i.e. baud rate) reduces bandwidth used for data transmission.
• Example application Raw data before modulation is measured in units or bits per sec. Modulated data after modulation is measured in units or symbols per sec or baud rate.