bipolar violation (BPV)
In various channel codings, several consecutive zeros are interrupted by a bit combination. This is referred to as code violations or code violations.
This is the case, for example, with B3ZS, B6ZS and B8ZS. The reason for this lies in the generation of the synchronization signal.
These forced bit combinations are called Bipolar Violation (BPV), they consist of two consecutive levels, one positive (+1) and one negative (-1), or vice versa. Which level state is used first depends on the level used for the last 1. If a positive level was used for the last 1, then the bipolar violation also starts with a positive level. In the other case with a negative level.