A method may include receiving a stream of datagrams, the datagrams having a first bit length. The method may also include selecting a block of bits from consecutively-received datagrams, the block having a second bit length greater than the first bit length. The method may additionally include determining whether a particular data field is present at a particular bit position within the block. The method may further include outputting the block as a valid block in response to determining that the particular data field is present at the particular bit position. The method may additionally include, in response to determining that the particular data field is not present at the particular bit position: discarding a received datagram from the stream of datagrams; and repeating the receiving, selecting, determining, and discarding steps until a determination is made that the particular data field is present at the particular bit position.