“Baud” is a unit of measurement that refers to the rate of signal transitions in a communication channel. Originally, baud was used to describe the number of signal changes (symbols) per second in analog communication systems, such as telegraphy and early modems. However, the term is often confused with “bps” (bits per second), which is a more accurate measure of data transmission speed in digital communication. Here’s the distinction:
Baud:
- Baud measures the number of signal changes (symbols or signal elements) per second.
- In analog systems, each symbol can represent more than one bit of information. For example, in Morse code, a symbol might represent a letter or a character.
Bits per Second (bps):
- Bits per second measures the number of individual binary data bits transmitted per second.
- In digital communication, each bit corresponds to a binary 0 or 1.
Relation Between Baud and bps:
- In some cases, baud and bps can be equal, especially in simple binary signaling systems where each symbol represents one bit (e.g., non-return-to-zero encoding).
- However, in more complex signaling schemes (e.g., quadrature amplitude modulation), multiple bits can be encoded per symbol, leading to a difference between baud and bps.
Example:
- Imagine a communication system where each symbol (baud) represents two bits of data. If the system transmits 1000 symbols per second, then the baud rate is 1000 baud. However, since each symbol carries 2 bits of data, the effective data rate is 2000 bps (bits per second).
Digital Communication:
- In modern digital communication, the distinction between baud and bps becomes less relevant, as many systems use modulation techniques where each symbol carries a fixed number of bits.
In summary, while baud was historically used to describe the rate of signal transitions in analog communication, it’s often more appropriate to use “bps” (bits per second) to describe the speed of data transmission in digital communication systems.