A channel decoder for a digital broadcast receiver having a synchronization byte detector for detecting synchronization bytes in a decoded transmission signal. The synchronization byte detector provides a synchronization signal indicating a start of frame for transport stream packets in the decoded transmission signal and provides a lock detected output signal indicating the lock-in of the receiver to one broadcast channel. The lock detected output signal is used as at least one of a feed forward signal and a feed back signal to switch processing stages at least one of succeeding and preceding, respectively, said synchronization byte detector into a different mode dependent on whether or not a lock has been achieved.