Embodiments of this application provide a method for coding in a wireless communication network. A communication device interleave a first bit sequence to obtain a first interleaved sequence having sequence number starting with a sequence number of 0, wherein the first bit sequence comprises bits for indicating timing, wherein the bits for indicating timing comprises a set of bits for indicating synchronization signal block index (SSBI); wherein the set of bits for indicating SSBI are placed in positions indicated by sequence numbers of 2, 3 and 5 in the first interleaved sequence. The devices then add d a first CRC bits on the first interleaved sequence to obtain a second bit sequence, then interleave on the second bit sequence according to an interleave pattern to obtain a second interleaved sequence, and finally polar encode the second interleaved sequence to obtain the encoded sequence.