differential biphase coding (DBP)

Differential Biphase Coding (DBP) is an edge coding. Here, only the binary zeros are encoded as a half-bit period. The amplitude changes from "0" to "1" at the half bit period and falls back to "0" with the following edge. If a binary one is present, the coding pattern remains unchanged. So that the receiver can generate a clock recovery from the data signal, the DBP signal is inverted at the start of each period.