TEPZZ 9 449B_T EP B1 (19) (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION. (51) Int Cl.:

Transcription

1 (19) TEPZZ 9 449B_T (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin 13/28 (21) Application number: (22) Date of filing: (1) Int Cl.: H03M 7/00 (06.01) H03M /14 (06.01) (86) International application number: PCT/CN09/ (87) International publication number: WO /1333 (2.11. Gazette /47) (4) Method and apparatus for generating a coding table Verfahren und Vorrichtung zum Generieren einer Codiertabelle Procédé et appareil pour générer une table de codage (84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR (43) Date of publication of application: Bulletin 11/ (73) Proprietor: Huawei Technologies Co., Ltd. Shenzhen, Guangdong (CN) (72) Inventors: FENG, Dongning Shenzhen (CN) GENG, Dongyu Shenzhen (CN) LEUNG, Raymond, W. K Shenzhen (CN) LI, Jing Shenzhen (CN) EFFENBERGER, Frank Shenzhen (CN) BENEDETTO, Sergio Shenzhen (CN) MONTORSI, Guido Shenzhen (CN) (74) Representative: Thun, Clemens et al Mitscherlich & Partner Patent- und Rechtsanwälte Sonnenstrasse München (DE) (6) References cited: CN-A JP-A US-B US-B US-B US-B US-B EFFENBERGER F ET AL: "A 9bb line code for 2.Gb/s upstream PONs", OPTICAL FIBER COMMUNICATION - INCUDES POST DEADLINE PAPERS, 09. OFC 09. CONFERENCE ON, IEEE, PISCATAWAY, NJ, USA, 22 March 09 ( ), pages 1-3, XP , ISBN: EP B1 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 Description FIELD OF THE INVENTION [0001] The present invention relates to communication technologies, and in particular, to a method and an apparatus for line coding. BACKGROUND 2 [0002] Line coding is widely applied in the Ethernet system. Line coding is designed to enable the point-to-point system to use cost-effective optical receiver. Due to Direct Current (DC) balance and the small number of DC components of line coding, the line coding is more suitable for the Ethernet Passive Optical Network (EPON) system. Common line coding modes include: 9BB line coding, 8BB line coding, 64B/66B line coding, and 64B/6B line coding. The 8BB coding efficiency is not high, and involves % redundancy. Neither the 64B/66B line coding nor the 64B/6B line coding solves the DC balance or ensures few DC components. Therefore, the 9BB line coding is a relatively better coding manner. [0003] In the current 9BB line coding, each control character corresponds to a 9-bit source, namely, there are 18 9-bit sources, where each 9-bit source corresponds to a -bit codeword and a -bit control character. For example, after "0 " is encoded, the " " is a -bit codeword, and the " " is a control character. If the last bit is erroneous due to channel noise, the receiver is unable to decode the bits correctly, and the performance is deteriorated. Therefore, a new 9BB line coding mode is required. [0004] US 6,747,80 B1, US 7,,679 B1 and Effenberger F ET AL; "A 9bb line code for 2.Gb/s upstream PONs", Optical Fiber Communication - includes post deadline papers, 09. OFC 09. Conference on, IEEE; Piscataway, NJ, USA, 22 March 09 ( ), pages 1-3, XP , ISBN: , describe methods and apparatuses for the construction of a 9BB line code and for the encoding and decoding of data in accordance with the 9BB line code. SUMMARY [000] As a first aspect a code table generating method for convolutional line coding is provided by the present invention. [0006] The method includes: 3 constructing a sequence set, where the length of each sequence in the sequence set is bits; selecting a balanced sequence in the sequence set, and obtaining source data of 9 bits corresponding to the balanced sequence; performing Hamming distance detection for the unbalanced sequence in the sequence set to obtain source data of 9 bits corresponding to the unbalanced sequence; and sorting the balanced sequence and the unbalanced sequence according to an operation, and generating a code table, where the source data of 9 bits correspond to the sequence of bits, the operation of a sequence is the between the number of 0s and the number of 1s and the code table is designed for line coding; 4 0 wherein for the balanced sequence, a first bit or a last bit of each -bit sequence is deleted to obtain 9 bits; and for the unbalanced sequence, a Hamming distance between the 9-bit source data and the -bit sequence is detected, and the -bit sequence corresponding to the 9-bit source data is obtained when the Hamming distance reaches a minimum ; and wherein the sequences are sorted according to the operation s to generate a 9BB code table corresponding to each operation, wherein the operation s are -4, -2, 0, 2, and 4; the code table whose operation is 0 is composed of 2 DC-balance -bit codewords; the code table whose operation is 62 is composed of 190 -bit codewords, and each codeword comprises six 1s and four 0s, or comprises six 0s and four 1s; the code table whose operation is 64 is composed of 82 -bit codewords, and each codeword comprises seven 1s and three 0s, or comprises seven 0s and three 1s. [0007] As a second aspect of the present invention. An apparatus for generating a coding table suitable for a convolutional line coder is provided herein. The coder includes: a sequence set obtaining module, configured to construct a sequence set, where the length of each sequence is bits; a relation associating module, configured to: select a balanced sequence in the sequence set, and obtain source 2

3 data of 9 bits corresponding to the balanced sequence; perform Hamming distance detection for the unbalanced sequence in the sequence set to obtain source data of 9 bits corresponding to the unbalanced sequence; and a coding module, configured to sort the balanced sequence and the unbalanced sequence according to an operation, and generate a code table, where the source data of 9 bits correspond to the sequence of n bits, the operation of a sequence is the between the number of 0s and the number of 1s and the code table is designed for line coding; wherein for the balanced sequence, a first bit or a last bit of each -bit sequence is deleted by the relation associating module to obtain 9 bits; and for the unbalanced sequence, a Hamming distance between the 9-bit source data and the -bit sequence is detected by relation associating module, and the -bit sequence corresponding to the 9-bit source data is obtained when the Hamming distance reaches a minimum ; and wherein the sequences are sorted by the coding module according to the operation s to generate a 9BB code table corresponding to each operation, wherein the operation s are -4, -2, 0, 2, and 4; the code table whose operation is 0 is composed of 2 DC-balance -bit codewords; the code table whose operation is 62 is composed of 190 -bit codewords, and each codeword comprises six 1s and four 0s, or comprises six 0s and four 1s; the code table whose operation is 64 is composed of 82 -bit codewords, and each codeword comprises seven 1s and three 0s, or comprises seven 0s and three 1s. [0008] The coding method provided herein obtains the source data of n-1 bits corresponding to the unbalanced sequence through Hamming distance detection, restricts the number of continuous 0s or 1s, and makes the amplitude limitable and controllable. The source data of n-1 bits correspond to the sequence of n bits uniquely, thus improving the coding performance. 2 BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a flowchart of a method according to an embodiment of the present invention; FIG. 2 is a state graph, corresponding to a 3-state lattice graph designed, according to an embodiment of the present invention; and FIG. 3 shows a structure of a convolutional line coder according to an example of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS 3 [00] The technical solution under the present invention is expounded below with reference to accompanying drawings. Evidently, the embodiments given herein are for the exemplary purpose only, and are not the entirety of the embodiments of the present invention. [0011] A new convolutional line coding method provided herein is suitable especially for optical communication. The code rate is R = (n-1)/n, and is suitable for state convolutional coders and Viterbi decoders. [0012] As shown in FIG. 1, a convolutional line coding method includes the following steps: 4 S1: Construct a sequence set, where the length of each sequence in the sequence set is n bits. n is a natural number greater than 1. This set includes balanced sequences and unbalanced sequences. All codewords in this set comply with w(α) W n, where α is any sequence of n bits in the set, w(α) is an operation of α, and w is a constant which is an even number. A balanced sequence refers to a sequence in which the number of 0s is equal to the number of 1s; and an unbalanced sequence refers to a sequence in which the number of 0s is unequal to the number of 1s. Alternatively, a balanced sequence refers to the sequence whose operation is 0, and an unbalanced sequence refers to the sequence whose operation is not 0. 0 [0013] The operation herein is defined as: the operation of a j-bit binary sequence s is the between the number of 0s and the number of 1s in the j-bit sequence s, namely, [0014] s i is a bit unit in the sequence s, and its range is {-1, +1}. That is, before the operation 3

4 is calculated, the range {0, 1} of s i needs to be mapped to {-1,+1}. [00] S2: Select a balanced sequence in the sequence set, and obtain source data of n-1 bits corresponding to the balanced sequence. [0016] In practice, the first or last bit in the balanced sequence may be deleted to obtain the source data of n-1 bits corresponding to the balanced sequence. [0017] S3: Perform Hamming distance detection for the unbalanced sequence in the sequence set to obtain source data of n-1 bits corresponding to the unbalanced sequence. [0018] When the Hamming distance reaches its minimum, the source data of n-1 bits corresponding to the unbalanced sequence is obtained. [0019] S4: Sort the balanced sequence and the unbalanced sequence according to the operation, and generate a code table corresponding to the source data of n-1 bits and the sequence of n bits. This code table is designed for line coding. At the time of encoding the source data of n-1 bits, a coding result of n bits is obtained according to the mapping relation in the code table. [00] The line coding method provided herein involves low redundancy, and is applicable to line coding of optical communication systems. It ensures a specific amount of 0 and 1 transients of code streams, and is conducive to clock recovery of the receiver of the optical transmission system. The coding method provided herein obtains the source data of n-1 bits corresponding to the unbalanced sequence through Hamming distance detection, restricts the number of continuous 0s or 1s, and makes the amplitude limitable and controllable. The source data of n-1 bits correspond to the sequence of n bits uniquely, thus improving the coding performance. [0021] Further, a W+1 state lattice graph is designed. Each lattice graph corresponds to a 2 n-1 n-bit sequence set. That is, a corresponding (n-1) BnB code table is created for each w+1 state. Alternatively, the (n-1) BnB code tables corresponding to all operation s obtained in S 4 may be aggregated into a total (n-1) BnB code table. The balanced sequence has only one corresponding (n-1) B source datum, and two unbalanced sequences correspond to one (n-1) B source datum. The two unbalanced sequences may be in a complementing relation or not. [0022] Taking n= as an example, the 9BB line coding method is described below. [0023] In this embodiment, W is set to 4, and then a w(α) 4 -bit sequence set is constructed. By setting W to 4, this embodiment decreases the maximum amplitude of the designed codeword. [0024] First, a -bit sequence set is constructed. In this embodiment, the sequence set includes the following -bit sequences: all -bit balanced sequences, a sequence of six 1s and four 0s, a sequence of six 0s and four 1s, a sequence of seven 1s and three 0s, and a sequence of seven 0s and three 1s. In practice, a total of 912 -bit sequences meet the foregoing conditions, and only 12 -bit sequences corresponding to the 9-bit source data are required as -bit codewords. Therefore, the codewords with many continuous 0s or 1s may be further removed. For example, the -bit codewords which have 4 or more bits of the same at the beginning or have or more bits of the same at the end may be deleted. [002] Afterward, all -bit balanced sequences in the -bit sequence set are selected, namely, five 1s and five Os. The first bit of each -bit balanced sequence is deleted to obtain 9 bits, which are 9-bit source data corresponding to the -bit codeword. Alternatively, the last bit of each -bit balanced sequence is deleted to obtain 9 bits, which are 9- bit source data corresponding to the -bit codeword. [0026] Perform Hamming distance detection for the unbalanced sequence in the -bit sequence set to obtain the 9- bit source data corresponding to the unbalanced sequence. A mapping relation is set up according to the principle that a minimum Hamming distance exists between the 9-bit source data and the -bit codeword. [0027] Afterward, the sequences are sorted according to the operation (or sorted in W+1 states) to generate the 9BB code table corresponding to each operation. Because W is set to 4, the obtained 9BB codeword has five different operation s: -4, -2, 0, 2, and 4. The code table whose operation is 0 is composed of 2 DC-balance -bit codewords; the code table whose operation is 62 is composed of 190 -bit codewords, and each codeword includes six 1s (or 0s) and four 0s (or 1s); the code table whose operation is 64 is composed of 82 -bit codewords, and each codeword includes seven 1s (or 0s) and three 0s (or Is). In practice, the code table obtained above may be searched in the coding. Given below are exemplary code tables. 4

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13 [0028] Further, a lattice graph of W+1= states is designed, and the five states correspond to -4, -2, 0, 2, and 4. In this embodiment, n is set to. In order to reduce complexity, a 3-state lattice graph is designed additionally. FIG. 2 is a state graph, corresponding to a 3-state lattice graph designed, according to an embodiment of the present invention. Each lattice graph corresponds to 12 -bit sequence sets, namely, a corresponding 9BB code table is created for each state. The solution under the present invention has three states: -2, 0, and +2. In this case, the operation still has five s: -4, -2, 0, 2, and 4. [0029] The 9BB code table corresponding to the state "-2" may be a combination of the code tables sorted according to the operation : 2 balanced codes plus 190 unbalanced codes whose operation is +2 plus 82 unbalanced codes whose operation is +4. [00] The 9BB code table corresponding to the state "0" may be a combination of the code tables sorted according to the operation : 2 balanced codes plus the first 136 codewords of the unbalanced code table whose operation is +2 plus the first 136 codewords of the unbalanced code table whose operation is -2. [0031] The 9BB code table corresponding to the state "+2" may be a combination of the code tables sorted according to the operation : 2 balanced codes plus 190 unbalanced codes whose operation is -2 plus 82 unbalanced codes whose operation is -4. [0032] The overall code table is as follows: 9B (decimal) Table 2 Code table B B

14 B (decimal) (continued) Code table B B

15 B (decimal) (continued) Code table B B

16 B (decimal) (continued) Code table B B

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18 B (decimal) (continued) Code table B B

19 B (decimal) (continued) Code table B B

20 B (decimal) (continued) Code table B B

21 B (decimal) (continued) Code table B B

22 B (decimal) (continued) Code table B B

23 B (decimal) (continued) Code table B B

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25 B (decimal) (continued) Code table B B

26 B (decimal) (continued) Code table B B

27 B (decimal) (continued) Code table B B

28 2 9B (decimal) (continued) Code table B B [0033] The line coding provided herein is applicable to the traditional coding and decoding methods based on table search. Further, a line coding method is provided in an example of the present invention. [0034] The line coding method in this example performs coding by searching the code table generated in the foregoing embodiment. The method includes: 4 performing 9BB line coding for every 9-bit source data according to a current operation of line coding, where the line coding is implemented by searching a code table, and the code table is shown in Table 2; calculating the coded operation ; and judging whether the coded operation is greater than a preset, and if the coded operation is greater than the preset, using the -bit sequence obtained through complementing the -bit codeword as the coding result corresponding to the 9-bit source data, where a judgment needs to be made about whether the operation exceeds the maximum allowed amplitude. [003] As shown in FIG. 3, a convolutional line coder is provided in an example of the present invention. The coder 0 includes: 0 a sequence set obtaining module 01, configured to construct a sequence set, where the length of each sequence is n bits; a relation associating module 02, configured to: select a balanced sequence in the sequence set, and obtain source data of n-1 bits corresponding to the balanced sequence; perform Hamming distance detection for the unbalanced sequence in the sequence set to obtain source data of n-1 bits corresponding to the unbalanced sequence; sort the balanced sequence and the unbalanced sequence according to an operation, and generate 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, obtain a coding result of n bits according to a mapping relation in the code table, where the relation associating module obtains the source data of n-1 bits corresponding to the balanced sequence by deleting the first bit or the last bit; and 28

29 a coding module 03, configured to: sort the balanced sequence and the unbalanced sequence according to the operation, and generate a code table, where the source data of n-1 bits corresponds to the sequence of n bits; at the time of encoding the source data of n-1 bits, obtain the coding result of n bits according to the mapping relation in the code table. [0036] The coding module 03 is further configured to calculate the coded operation. [0037] The coder 0 further includes a complementing module 04, configured to use the n-bit sequence obtained through complementing the n-bit codeword as the coding result corresponding to the source data of n-1 bits if the coded operation is greater than a preset. The coder 0 may further include a comparing module, which is configured to check whether the coded operation is greater than a preset. The comparing module may be independent of or combined with the coding module 03 or complementing module 04. [0038] Persons of ordinary skill in the art may understand that all or a part of the steps of the method according to the embodiments of the present invention may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium, such as a Read-Only Memory (ROM), a Random Access Memory (RAM) a magnetic disk or a Compact Disk Read-Only Memory (CD-ROM). Claims 1. A code table generating method for convolutional line coding, comprising: 2 3 constructing (S1) a sequence set, wherein a length of each sequence in the sequence set is bits; selecting (S2) a balanced sequence in the sequence set, and obtaining source data of 9 bits corresponding to the balanced sequence; performing (S3) Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of 9 bits corresponding to the unbalanced sequence; and sorting (S4) the balanced sequence and the unbalanced sequence according to operation s, and generating a code table, wherein the source data of 9 bits corresponds to the sequence of bits, the operation of a sequence is the between the number of 0s and the number of 1s and the code table is designed for line coding; wherein for the balanced sequence, a first bit or a last bit of each -bit sequence is deleted to obtain 9 bits; and for the unbalanced sequence, a Hamming distance between the 9-bit source data and the -bit sequence is detected, and the -bit sequence corresponding to the 9-bit source data is obtained when the Hamming distance reaches a minimum ; characterized in that, the sequences are sorted according to the operation s to generate a 9BB code table corresponding to each operation, wherein the operation s are -4, -2, 0, 2, and 4; the code table whose operation is 0 is composed of 2 DC-balance -bit codewords; the code table whose operation is 62 is composed of 190 -bit codewords, and each codeword comprises six 1s and four 0s, or comprises six 0s and four 1s; the code table whose operation is 64 is composed of 82 -bit codewords, and each codeword comprises seven 1s and three 0s, or comprises seven 0s and three Is An apparatus for generating a coding table suitable for a convolutional line coder, comprising: a sequence set obtaining module (01), configured to construct a sequence set, wherein a length of each sequence is bits; a relation associating module (02), configured to select a balanced sequence in the sequence set, and obtain source data of 9 bits corresponding to the balanced sequence; and to perform Hamming distance detection for an unbalanced sequence in the sequence set to obtain source data of 9 bits corresponding to the unbalanced sequence; and a coding module (03), configured to sort the balanced sequence and the unbalanced sequence according to operation s, and generate a code table, wherein the source data of 9 bits corresponds to the sequence of bits, the operation of a sequence is the between the number of 0s and the number of 1s and the code table is designed for line coding; wherein for the balanced sequence, a first bit or a last bit of each -bit sequence is deleted by the relation associating module (02) to obtain 9 bits; and for the unbalanced sequence, a Hamming distance between the 9-bit source data and the -bit sequence is 29

30 detected by relation associating module (02), and the -bit sequence corresponding to the 9-bit source data is obtained when the Hamming distance reaches a minimum ; characterized in that, the sequences are sorted by the coding module (03) according to the operation s to generate a 9BB code table corresponding to each operation, wherein the operation s are -4, -2, 0, 2, and 4; the code table whose operation is 0 is composed of 2 DC-balance -bit codewords; the code table whose operation is 62 is composed of 190 -bit codewords, and each codeword comprises six 1s and four 0s, or comprises six 0s and four 1s; the code table whose operation is 64 is composed of 82 -bit codewords, and each codeword comprises seven 1s and three 0s, or comprises seven 0s and three Is. Patentansprüche 1. Codetabellen-Erzeugungsverfahren zur Faltungs-Leitungscodierung, umfassend: 2 3 Konstruieren (S1) einer Sequenzmenge, wobei eine Länge jeder Sequenz in der Sequenzmenge Bit beträgt; Auswählen (S 2) einer ausgeglichenen Sequenz in der Sequenzmenge und Erhalten von Quellendaten von 9 Bit entsprechend der ausgeglichenen Sequenz; Ausführen (S 3) von Hamming-Distanz-Detektion für eine nicht ausgeglichene Sequenz in der Sequenzmenge, um Quellendaten von 9 Bit entsprechend der nicht ausgeglichenen Sequenz zu erhalten; und Sortieren (S4) der ausgeglichenen Sequenz und der nicht ausgeglichenen Sequenz gemäß sdifferenzwerten und Erzeugen einer Codetabelle, wobei die Quellendaten von 9 Bit der Sequenz von Bit entsprechen, der sdifferenzwert einer Sequenz die Differenz zwischen der Anzahl von 0en und der Anzahl von 1 en ist und die Codetabelle für Leitungscodierung ausgelegt ist; wobei bei der ausgeglichenen Sequenz ein erstes Bit oder ein letztes Bit jeder -Bit-Sequenz gelöscht wird, um 9 Bit zu erhalten; und bei der nicht ausgeglichenen Sequenz eine Hamming-Distanz zwischen den 9-Bit-Quellendaten und der - Bit-Sequenz detektiert wird und die -Bit-Sequenz entsprechend den 9-Bit-Quellendaten erhalten wird, wenn die Hamming-Distanz einen Minimalwert erreicht; dadurch gekennzeichnet, dass die Sequenzen gemäß den sdifferenzwerten sortiert werden, um eine 9BB-Codetabelle entsprechend jedem sdifferenzwert zu erzeugen, wobei die sdifferenzwerte -4, -2, 0, 2 und 4 sind; die Codetabelle, deren sdifferenzwert 0 ist, aus 2 DC-Ausgleichs--Bit-Codewörtern zusammengesetzt ist; die Codetabelle, deren sdifferenzwert 62 ist, aus 190 -Bit-Codewörtern zusammengesetzt ist und jedes Codewort sechs 1 en und vier 0en umfasst oder sechs 0en und vier 1en umfasst; die Codetabelle, deren sdifferenzwert 64 ist, aus 82 -Bit-Codewörtern zusammengesetzt ist und jedes Codewort sieben 1en und drei 0en umfasst oder sieben 0en und drei 1en umfasst. 2. Vorrichtung zum Erzeugen einer Codierungstabelle, die für einen Faltungs-Leitungscodierer geeignet ist, umfassend: 4 0 ein Sequenzmengen-Erhaltemodul (01), das dafür ausgelegt ist, eine Sequenzmenge zu konstruieren, wobei eine Länge jeder Sequenz Bit beträgt; ein Relationsassoziationsmodul (02), das dafür ausgelegt ist, eine ausgeglichene Sequenz in der Sequenzmenge auszuwählen und Quellendaten von 9 Bit entsprechend der ausgeglichenen Sequenz zu erhalten; und Hamming-Distanz-Detektion für eine nicht ausgeglichene Sequenz in der Sequenzmenge auszuführen, um Quellendaten von 9 Bit entsprechend der nicht ausgeglichenen Sequenz zu erhalten; und ein Codierungsmodul (03), das dafür ausgelegt ist, die ausgeglichene Sequenz und die nicht ausgeglichene Sequenz gemäß sdifferenzwerten zu sortieren und eine Codetabelle zu erzeugen, wobei die Quellendaten von 9 Bit der Sequenz von Bit entsprechen, der sdifferenzwert einer Sequenz die Differenz zwischen der Anzahl von 0en und der Anzahl von 1en ist und die Codetabelle für Leitungscodierung ausgelegt ist; wobei bei der ausgeglichenen Sequenz ein erstes Bit oder ein letztes Bit jeder -Bit-Sequenz durch das Relationsassoziationsmodul (02) gelöscht wird, um 9 Bit zu erhalten; und bei der nicht ausgeglichenen Sequenz eine Hamming-Distanz zwischen den 9-Bit-Quellendaten und der - Bit-Sequenz durch das Relationsassoziationsmodul (02) detektiert wird und die -Bit-Sequenz entsprechend den 9-Bit-Quellendaten erhalten wird, wenn die Hamming-Distanz einen Minimalwert erreicht;

31 dadurch gekennzeichnet, dass die Sequenzen gemäß den sdifferenzwerten durch das Codierungsmodul (03) sortiert werden, um eine 9BB-Codetabelle entsprechend jedem sdifferenzwert zu erzeugen, wobei die sdifferenzwerte -4, -2, 0, 2 und 4 sind; die Codetabelle, deren sdifferenzwert 0 ist, aus 2 DC-Ausgleichs- -Bit-Codewörtern zusammengesetzt ist; die Codetabelle, deren sdifferenzwert 62 ist, aus Bit-Codewörtern zusammengesetzt ist und jedes Codewort sechs 1en und vier 0en umfasst oder sechs 0en und vier 1en umfasst; die Codetabelle, deren sdifferenzwert 64 ist, aus 82 -Bit-Codewörtern zusammengesetzt ist und jedes Codewort sieben 1en und drei 0en umfasst oder sieben 0en und drei 1en umfasst. Revendications 1. Procédé de génération de table de code pour codage de ligne convolutionnel, consistant à : 2 - construire (S1) un ensemble de séquences dans lequel une longueur de chaque séquence dans l ensemble de séquences est de bits ; - choisir (S2) une séquence équilibrée dans l ensemble de séquences, et obtenir des données sources de 9 bits correspondant à la séquence équilibrée ; - effectuer une détection de distance Hamming (S3) d une séquence déséquilibrée dans l ensemble de séquences afin d obtenir des données sources de 9 bits correspondant à la séquence déséquilibrée ; et - trier (S 4) la séquence équilibrée et la séquence déséquilibrée en fonction de valeurs de différence d opération et générer une table de codes, dans lequel les données sources de 9 bits correspondent à la séquence de bits, la valeur de différence d opération d une séquence est la différence entre le nombre de 0 et le nombre de 1, et la table de codes est conçue pour le codage de lignes ; dans lequel, pour la séquence équilibrée, un premier bit ou un dernier bit de chaque séquence de bits est effacé pour obtenir 9 bits ; et pour la séquence déséquilibrée, une distance Hamming entre les données sources de 9 bits et la séquence de bits est détectée, et la séquence de bits correspondant aux données sources de 9 bits est obtenue lorsque la distance Hamming atteint une valeur minimale ; caractérisé en ce que : 3 - les séquences sont triées en fonction de valeurs de différences d opération afin de générer une table de codes 9BB correspondant à chaque valeur de différence d opération, dans lequel les valeurs de différences d opération sont -4, -2, 0, 2 et 4 ; la table de codes dont la valeur de différence d opération est 0 comprend 2 mots de code bits d équilibrage CC ; la table de codes dont la valeur de différence d opération est 62 comprend 190 mots de code bits et chaque mot de code comprend six 1 et quatre 0 ou comprend six 0 et quatre 1 ; la table de codes dont la valeur de différence d opération est de 64 comprend 82 mots de code bits, et chaque mot de code comprend sept 1 et trois 0 ou comprend sept 0 et trois Appareil pour générer une table de codage adaptée pour un codeur de ligne convolutionnel, comprenant : un module d obtention d ensemble de séquences (01) conçu pour construire un ensemble de séquences dans lequel une longueur de chaque séquence est de bits ; - un module d association de relations (02) conçu pour choisir une séquence équilibrée dans l ensemble de séquences, et obtenir des données sources de 9 bits correspondant à la séquence équilibrée, et effectuer une détection de distance Hamming d une séquence déséquilibrée dans l ensemble de séquences afin d obtenir des données sources de 9 bits correspondant à la séquence déséquilibrée ; et - un module de codage (03) conçu pour trier la séquence équilibrée et la séquence déséquilibrée en fonction de valeurs de différence d opération et générer une table de codes, dans lequel les données sources de 9 bits correspondent à la séquence de bits, la valeur de différence d opération d une séquence est la différence entre le nombre de 0 et le nombre de 1, et la table de codes est conçue pour le codage de lignes ; dans lequel, pour la séquence équilibrée, un premier bit ou un dernier bit de chaque séquence de bits est effacé par le module d association de relations (02) pour obtenir 9 bits ; et pour la séquence déséquilibrée, une distance Hamming entre les données sources de 9 bits et la séquence de bits est détectée par le module d association de relations (02), et la séquence de bits correspondant aux données sources de 9 bits est obtenue lorsque la distance Hamming atteint une valeur minimale; 31

32 caractérisé en ce que : - les séquences sont triées par le module de codage (03) en fonction de valeurs de différences d opération afin de générer une table de codes 9BB correspondant à chaque valeur de différence d opération, dans lequel les valeurs de différences d opération sont -4, -2, 0, 2 et 4 ; la table de codes dont la valeur de différence d opération est 0 comprend 2 mots de code bits d équilibrage CC ; la table de codes dont la valeur de différence d opération est 62 comprend 190 mots de code bits et chaque mot de code comprend six 1 et quatre 0 ou comprend six 0 et quatre 1 ; la table de codes dont la valeur de différence d opération est de 64 comprend 82 mots de code bits, et chaque mot de code comprend sept 1 et trois 0 ou comprend sept 0 et trois

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35 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description US B1 [0004] US 7679 B1 [0004] Non-patent literature cited in the description EFFENBERGER F et al. A 9bb line code for 2.Gb/s upstream PONs. Optical Fiber Communication, 22 March 09, ISBN , 1-3 [0004] 3