User station for a serial bus system, and method for communicating in a serial bus system

A bus system, comprising:

• a bus;
• and
• at least two user stations that are connected to one another via the bus in such a way that they may communicate serially with one another, and of which at least one user station includes:
• a communication control device configured to control a communication of the user station with at least one other user station of the bus system;
• and
• a transceiver device configured to transmit a transmission signal, generated by the communication control device, onto the bus of the bus system, so that for a message that is exchanged between user stations of the bus system, a bit time of a signal transmitted onto the bus in the first communication phase is different from a bit time of a signal transmitted in the second communication phase;
• wherein the communication control device is configured to generate the transmission signal according to a frame in which a field for a header check sum and a field for a frame check sum are provided, the communication control device being configured to provide an identifier in the frame which indicates a priority for transmitting the exchanged message onto the bus, and the communication control device being configured to compute the header check sum from all bits in a header of the frame that is formed for the message, with the exception of fixed stuff bits that have been inserted into the header of the frame according to a fixed bit stuffing rule, according to which a fixed stuff bit is to be inserted after a fixed number of bits.