- In bipolar encoding, we use three levels: positive, zero, and negative Zero level in bipolar encoding is used to represent binary 0.
- The 1s are represented by alternating positive and negative voltages.
- AMI = Alternate Mark Inversion
- Unipolar encoding uses only one voltage level
- Unipolar encoding is so named because it uses only one polarity.
- Polarity is assigned to one of the two binary states, usually the 1.
- The other state, usually the 0, is represented by zero voltage.
- Has dc component.
- Lack of synchronization is an issue in unipolar encoding.
- the transition at the middle of the bit is used only for synchronization.
- The bit representation is defined by the inversion or noninversion at the beginning of the bit.
- A transition means binary 0, and no transition means binary 1.
- the transition at the middle of the bit is used for both synchronization and bit representation
- A good encoded digital signal
- must contain a provision for synchronization
RZ
- The signal is inverted if a 1 is encountered
- A 0 bit is represented by no change
NRZ-I
- The level of the signal is dependent upon the state of the bit
- Positive voltage usually means the bit is 0
- Negative voltage usually means the bit is 1
NRZ-L
DIFFERENTIAL MANCHESTER
MANCHESTER
POLAR
BIPOLAR
UNIPOLAR
LINE CODING is the process of converting binary data, a sequence of bits, to a digital signal.
