A network device polar encodes data to obtain a first encoded bit sequence, wherein the first encoded bit sequence comprises: bits in even number locations in the first encoded bit sequence and bits in odd number locations in the first encoded bit sequence; then the device interleaves the first encoded bit sequence to obtain an interleaved bit sequence; finally, the device rate matches the interleaved bit sequence and outputs the bit sequence after rate matched, wherein bits in even number locations of the interleaved bit sequence are from the bits in even number locations of the first encoded bit sequence, bits in odd number locations of the interleaved bit sequence are from the bits in odd number locations of the first encoded bit sequence.