Manchester code and differential Manchester code

The self-synchronization method refers to the method that can extract the synchronous signal from the data signal waveform. A typical example is the famous Manchester code, which is often used for LAN transmission. In Manchester Coding, there is a hop in the middle of each bit. The hop in the middle is both a clock signal and a data signal. The hop in the middle is 1 ", the jump from low to high indicates "0 ". There is also a differential Manchester code. The hop in the middle only provides the clock timing, and each hop in the beginning indicates "0" or "1 ", A hop changes to "0" and a hop does not change to "1 ".
The two Manchester encodings are used to include the clock and data in the data stream.CodeAt the same time, the clock synchronization signal is also transmitted to the other party, each encoding has a hop change, there is no DC component, so it has the ability of self-synchronization and good anti-interference performance. However, every code element is adjusted to two levels, so the data transmission rate is only 1/2 of the modulation rate.
That is to say, it is mainly used in the encoding method of data synchronization transmission.