Principles Digital Communication System & Computer Networks (Charles River Media Computer Engineering)

6.4 NON-RETURN TO ZERO LEVEL (NRZ-L)

In NRZ-L, binary 1 is represented by positive voltage and 0 by negative voltage. This scheme, though simple, creates problems: if there is a synchronization problem, it is difficult for the receiver to synchronize, and many bits are lost.

In NRZ-L, 1 is represented by positive voltage and 0 by negative voltage. Synchronization is a problem in this encoding scheme.