The present invention relates to channel decoding and provides ways and means for improved channel decoding of data frames. The frame has been channel encoded and transmitted to a receiver. The frame includes a part with information that is unknown to the receiver and another part with information for which the receiver generates at least one data hypothesis predicting its information content. The receiver performs a hypothesis-based decoding of the received encoded frame, wherein the at least one data hypothesis is used to improve a probability of successful decoding. The invention may advantageously be used to improve decoding of frames containing short control messages with fill bits, e.g. acknowledgement messages.