Abstract: A method for encoding or decoding an LDPC code with variable code lengths is provided in an embodiment of the present invention. The method includes: obtaining a base exponential matrix of an LDPC code and grouping code lengths during construction of the base exponential matrix; correcting the base exponential matrix according to a grouping correction factor to obtain an exponential matrix of the group corresponding to the grouping correction factor; extending the exponential matrix by using an extension factor of a code length in the group to obtain an LDPC matrix corresponding to the code length; and implementing encoding or decoding by using the LDPC matrix.

Abstract: The present invention provides a convolutional line coding method, including: constructing a sequence set, where the length of each sequence in the sequence set is n bits; selecting a balanced sequence in the sequence set, and obtaining source data of n?1 bits corresponding to the balanced sequence; performing Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of n?1 bits corresponding to the unbalanced sequence; sorting the balanced sequence and the unbalanced sequence according to an operation difference value, and generating a code table, where the source data of n?1 bits correspond to the sequence of n bits, and the code table is designed for line coding; and at time of encoding the source data of n?1 bits, obtaining a coding result of n bits according to a mapping relation in the code table.

Abstract: The present disclosure relates to the Passive Optical Network (PON) technology, and a method for sending an upstream transfer frame in a PON is provided, so as to improve flexibility of a system and satisfy a requirement that an error probability is reduced as low as possible. The method includes: after success of link, sending a preamble according to an allocated time slot, sending a burst synchronization delimiter, and then sending successively a burst header, a Gigabit-Capable Passive Optical Network (GPON) Transmission Convergence (GTC) frame header, and GTC frame data. In the sent synchronization delimiter, the number of non-zeros is the same as the number of zeros, and in a delimiter sequence, the number of non-zeros on odd bits is equal to the number of zeros on even bits, and the number of non-zeros on even bits is equal to the number of zeros on odd bits.

Abstract: The present invention relates to the Passive Optical Network (PON) technology, and a method for sending an upstream transfer frame in a PON is provided, so as to improve flexibility of a system and satisfy a requirement that an error probability is reduced as low as possible. The method includes: after success of link, sending a preamble according to an allocated time slot, sending a burst synchronization delimiter, and then sending successively a burst header, a Gigabit-Capable Passive Optical Network (GPON) Transmission Convergence (GTC) frame header, and GTC frame data.

Abstract: A method for encoding or decoding an LDPC code with variable code lengths is provided in an embodiment of the present invention. The method includes: obtaining a base exponential matrix of an LDPC code and grouping code lengths during construction of the base exponential matrix; correcting the base exponential matrix according to a grouping correction factor to obtain an exponential matrix of the group corresponding to the grouping correction factor; extending the exponential matrix by using an extension factor of a code length in the group to obtain an LDPC matrix corresponding to the code length; and implementing encoding or decoding by using the LDPC matrix.

Abstract: The present invention provides a convolutional line coding method, including: constructing a sequence set, where the length of each sequence in the sequence set is n bits; selecting a balanced sequence in the sequence set, and obtaining source data of n?1 bits corresponding to the balanced sequence; performing Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of n?1 bits corresponding to the unbalanced sequence; sorting the balanced sequence and the unbalanced sequence according to an operation difference value, and generating a code table, where the source data of n?1 bits correspond to the sequence of n bits, and the code table is designed for line coding; and at time of encoding the source data of n?1 bits, obtaining a coding result of n bits according to a mapping relation in the code table.