The number of signal events, signal changes, or signal transitions occurring per second over an analog circuit, such as changes from positive voltage to zero voltage, from zero voltage to negative voltage, or from positive voltage to negative voltage. The baud rate can never be higher than the raw bandwidth of the channel, as measured in Hz. Baud rate and bit rate, often and incorrectly, are used interchangeably.The relationship between baud rate and bit rate depends on the sophistication of the modulation scheme used to manipulate the carrier. The bit rate and baud rate can be the same, if each bit is represented by a signal transition in a unibit modulation scheme.The bit rate can be higher that the baud rate, as a single signal transition can, and generally does, represent multiple bits. See also bit rate, carrier, and modulation.