COSC 85B PART 1

is the transmission of signals that vary discretely with time between two values of some physical quantity, on value representing binary 0 and 1.

digital data is assigned to one voltage level to binary 1 and another for binary 0.

Analog data such as video and voice are often digitized to be able to use digital transmission facilities.

is the representation of digital information by a digital signal.

– in this scheme, all the signal levels are either above or below the axis.

e are on the both sides of the axis.

there are three voltage levels: positive, negative, and zero. Voltage level for one data element is at zero, while voltage level for the other element alternates between positive and negative.

– positive voltage defines bit 1 and zero voltage defines bit 0.

– Inversion of the voltage level that represents 1 bit.

Signal changes between bits. RZ uses three voltage levels: o 1 – Positive Voltage o 0 – Negative Voltage o Zero – None