Coding and decoding method of five-order RLL (1, 4) modulation code and reading and writing method

Abstract

The application discloses a five-order RLL(1,4) modulation code coding and decoding method and a reading and writing method, belongs to the optical storage technical field, and comprises the following steps: a coding step: dividing user data into 5-bit source data, starting from an initial state, converting the source data into 4-bit channel code elements according to a pre-established coding and decoding table, and splicing the 4-bit channel code elements in sequence to obtain an RLL sequence; a decoding step: dividing the RLL sequence into 4-bit channel code elements, converting the 4-bit channel code elements into 5-bit source data according to the coding and decoding table in sequence, splicing the 5-bit source data in sequence, and obtaining user data; wherein the coding and decoding table is used for recording the mapping relationship between 32 kinds of 5-bit source data and 96 kinds of 5-bit channel code elements in a 3-state mode and the state of the next group of mapping relationships, and the channel code elements are 96 in 000X, 00X0, 0X00, 0X0X, X000, X0X0 and X00X; the value of X is 1-4. The application can significantly improve the capacity of an optical storage system without changing optical parameters.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical storage technology, and more particularly relates to a coding and decoding method and a reading and writing method of a five-order RLL(1,4) modulation code. BACKGROUND

[0002] With the advent of the digital era, the demand for information storage is growing, and it is predicted that the total amount of data generated globally will reach 175 zettabytes (ZB) by 2025, of which 80% (140 ZB) is cold data that is less frequently accessed. According to the principle of three off-site backups, 420 ZB of data capacity needs to be saved. At the present stage, mechanical hard disks, magnetic tapes, and Blu-ray discs are the mainstream storage media for storing cold data. Compared with mechanical hard disks and magnetic tapes, optical storage technology has the advantages of long storage life, low cost, high security, strong scalability, and low management cost. However, compared with mechanical hard disks and magnetic tapes, the single-disc storage capacity of Blu-ray discs based on optical storage technology is relatively low. In order to meet the growing demand for storage, it is of great significance to improve the storage capacity of optical storage devices. As a storage medium for storing cold data, the conventional optical storage technology often improves the storage capacity of optical storage devices by reducing the size of the focused laser spot and the recording symbol on the medium. However, due to the limitation of the optical diffraction limit, it is increasingly difficult to improve the capacity of optical discs using conventional optical storage technology.

[0003] In the conventional optical storage technology, in order to ensure the stability and reliable readout of the signal, run-length limited modulation coding (RLL) has been widely used. However, the run-length limited modulation coding used in the relatively mature products on the market is mostly two-order, and the symbols obtained by the coding are binary numbers of 0 and 1. At the present stage, the material of the optical storage medium itself has multi-order nature and can present different states, which can be used to store different information. Compared with the conventional two-order run-length limited coding, the multi-order run-length limited coding can better utilize the multi-order nature of the material and improve the capacity of the optical storage device. However, blindly increasing the coding order may lead to the inability of the optical storage medium to stably and reliably store data, and the pressure on signal detection is multiplied.

[0004] In a patent document with the application publication number CN116343836A, a fourth-order RLL(1, 7) code is disclosed, which realizes fourth-order run-length limited modulation coding. The minimum run length and the maximum run length are 2 and 8 respectively, the corresponding density coefficient theoretical value is 2.40, and the capacity theoretical value is 1.202. The density coefficient and the capacity are considered, and the capacity of the optical storage system is effectively improved without changing the optical parameters of the optical storage system. In the coding scheme, 6-bit source data is encoded into 5-bit channel symbols and 1-bit merging bit. Since the processing of the merging bit is involved in the encoding and decoding process, the encoding and decoding complexity is high. Moreover, the encoding efficiency of the encoding and decoding scheme is 6 / 6 = 1, which needs to be further improved for realizing large-capacity optical storage.

[0005] In a patent document with the application number CN117558299A, a fourth-order RLL(1, 3) modulation code is disclosed, which also realizes fourth-order run-length limited modulation coding. The minimum run length and the maximum run length are 1 and 3 respectively, the corresponding density coefficient density value is 2.31, and the capacity theoretical value is 1.154. During encoding, 4-bit source data is encoded into 4-bit channel symbols. This scheme avoids the processing of the additional merging bit by using a state-dependent encoding and decoding scheme, effectively reducing the encoding and decoding complexity. However, compared with the fourth-order RLL(1, 7) code, the density coefficient and the capacity of this scheme are decreased, and the encoding efficiency is 4 / 4 = 1, which still needs to be further improved for realizing large-capacity optical storage. SUMMARY

[0006] In view of the defects of the prior art and the improvement needs, the present application provides an encoding and decoding method of a fifth-order RLL(1, 4) modulation code and a reading and writing method, which aims to improve the encoding efficiency without affecting the density coefficient and the capacity of the optical storage system.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present application, an encoding and decoding method of a fifth-order RLL(1, 4) modulation code is provided, which comprises: an encoding step and a decoding step.

[0008] The encoding step comprises: dividing user data into source data with a length of 5 bits to obtain a source data sequence; setting the encoding and decoding state of the first source data to state A, then traversing the source data sequence, for each traversed source data, converting it into 4-bit channel symbols according to a pre-established encoding and decoding table, and determining the encoding and decoding state corresponding to the next traversed source data; after the traversal is completed, splicing the channel symbols in order to obtain an RLL sequence.

[0009] The decoding step comprises: dividing the RLL sequence to be decoded into 4-bit channel symbols to obtain a channel symbol sequence; setting the coding and decoding state of the first channel code to state A, then traversing the channel symbol sequence, for each traversed channel symbol, converting it to 5-bit source data according to the coding and decoding table, and determining the coding and decoding state corresponding to the next traversed channel symbol; after the traversal is completed, splicing the source data in order to obtain user data;

[0010] The coding and decoding table is used to record the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols in different coding and decoding states, and the coding and decoding state of the next group of mapping relationships of each group of mapping relationships; the different coding and decoding states are state A, state B and state C; in state A, the 32 kinds of 4-bit channel symbols are 32 kinds of 000X, 00X0, 0X00 and 0X0X, and the coding and decoding states of the next group of mapping relationships corresponding to the channel symbols 000X, 00X0, 0X00 and 0X0X are state A, state B, state C and state A respectively; in state B, the 32 kinds of 4-bit channel symbols are 32 kinds of 000X, 00X0, 0X00, X000 and X0X0, and the coding and decoding states of the next group of mapping relationships corresponding to the channel symbols 000X, 00X0, 0X00, X000 and X0X0 are state A, state B, state C and state B respectively; in state C, the 32 kinds of 4-bit channel symbols are 32 kinds of X00X and 0X0X, and the coding and decoding state of the next group of mapping relationships corresponding to the channel symbols X00X and 0X0X is state A; the value of X is 1-4.

[0011] Further, the elements in the coding and decoding table are represented in the format of {(D, S), NS}, wherein D represents source data, S represents the mapped channel symbol, and NS represents the coding and decoding state corresponding to the next group of mapping relationships, and state A, state B and state C are denoted as A, B and C respectively, then:

[0012] In state A, the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols, and the coding state of the next group of mapping relationships of each group of mapping relationships are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 0010), C}, {(01101, 0020), C}, {(01110, 0030), C}, {(01111, 0040), C}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010, 0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110, 0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010, 0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110, 0403), A}, {(11111, 0404), A};

[0013] In state B, the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols, and the coding state of the next group of mapping relationships of each group of mapping relationships are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 1000), C}, {(01101, 2000), C}, {(01110, 3000), C}, {(01111, 4000), C}, {(10000, 1010), B}, {(10001, 1020), B}, {(10010, 1030), B}, {(10011, 1040), B}, {(10100, 2010), B}, {(10101, 2020), B}, {(10110, 2030), B}, {(10111, 2040), B}, {(11000, 3010), B}, {(11001, 3020), B}, {(11010, 3030), B}, {(11011, 3040), B}, {(11100, 4010), B}, {(11101, 4020), B}, {(11110, 4030), B}, {(11111, 4040), B};

[0014] In the state C, the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols, and the coding state of the next group of mapping relationship of each group of mapping relationship are as follows: {(00000, 1001), A}, {(00001, 1002), A}, {(00010, 1003), A}, {(00011, 1004), A}, {(00100, 2001), A}, {(00101, 2002), A}, {(00110, 2003), A}, {(00111, 2004), A}, {(01000, 3001), A}, {(01001, 3002), A}, {(01010, 3003), A}, {(01011, 3004), A}, {(01100, 0010), A}, {(01101, 0020), A}, {(01110, 0030), A}, {(01111, 0040), A}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010, 0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110, 0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010, 0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110, 0403), A}, {(11111, 0404), A}.

[0015] According to still another aspect of the present application, there is provided an optical storage controller, comprising:

[0016] a computer readable storage medium for storing a computer program;

[0017] and a processor for reading the computer program stored in the computer readable storage medium and executing the above-mentioned coding and decoding method of the five-order RLL(1, 4) modulation code.

[0018] According to still another aspect of the present application, there is provided a read-write method of an optical storage system, comprising: a write operation and a read operation;

[0019] the write operation comprises:

[0020] encoding the user data into the RLL sequence by using the encoding step of the above-mentioned coding and decoding method of the five-order RLL(1, 4) modulation code;

[0021] modulating the RLL sequence obtained by encoding to obtain an NRZ sequence to be written;

[0022] writing the NRZ sequence to be written into an optical storage medium of an optical storage system;

[0023] The read operation comprises:

[0024] reading target data from the optical storage medium to obtain an NRZ sequence;

[0025] inverse NRZ modulating the NRZ sequence read from the optical storage medium to obtain an RLL sequence;

[0026] The decoding step of the encoding and decoding method of the five-order RLL (1, 4) modulation code provided by the present application is used to demodulate the RLL sequence obtained by inverse modulation to obtain user data.

[0027] Further, in the read operation, before inverse NRZ modulating the NRZ sequence read from the optical storage medium, it further comprises: detecting an error waveform in the NRZ sequence to be decoded which does not conform to the run length constraint and correcting it so that the NRZ sequence conforms to the run length constraint;

[0028] The run length constraint is that the number of continuous and identical signals is greater than or equal to 2 and less than or equal to 5.

[0029] Further, detecting an error waveform in the NRZ sequence to be decoded which does not conform to the run length constraint and correcting it comprises the following steps:

[0030] S0: setting a sliding window with a length of N at the head of the NRZ sequence;

[0031] S1: dividing the signals in the sliding window into signal groups; each signal group is composed of a single signal or a plurality of identical and continuous signals, and adjacent signal groups contain different code symbol;

[0032] S2: counting the number of signals contained in each signal group to detect whether each signal group conforms to the run length constraint;

[0033] S3: if the signal group G h conforms to the run length constraint, sliding the sliding window to the rear to the signal group G h removed, and then proceeding to step S5; otherwise, proceeding to step S4;

[0034] S4: if the number of signals contained in the signal group G h is less than 2, correcting the next signal of the signal group G h to a signal in the signal group G h to update the signal group G hSliding the sliding window backward to the signal group G h and then going to step S5; if the signal group G h contains more than 5 signals, the signal group G h is modified to the signal group G h containing the signal next to the signal at the 6th position of the signal group G h , and then going to step S5. h , and then going to step S5.

[0035] S5: if there are still signals in the sliding window, go to step S1; otherwise, the modification is over.

[0036] wherein N≥8.

[0037] Further, N=10.

[0038] According to still another aspect of the present application, there is provided a read-write device of an optical storage system, comprising: a write module and a read module.

[0039] The write module comprises:

[0040] an encoding unit configured to encode user data into an RLL sequence by using the encoding step of the encoding and decoding method of the five-order RLL(1,4) modulation code provided by the present application;

[0041] a modulation unit configured to modulate the RLL sequence obtained by encoding into an NRZ sequence to obtain an NRZ sequence to be written;

[0042] and a writing unit configured to write the NRZ sequence to be written into an optical storage medium of an optical storage system;

[0043] The read module comprises:

[0044] a reading unit configured to read target data from the optical storage medium to obtain an NRZ sequence;

[0045] an inverse modulation unit configured to inversely modulate the NRZ sequence read from the optical storage medium into an RLL sequence;

[0046] and a decoding unit configured to demodulate the RLL sequence obtained by using the inverse modulation by using the decoding step of the encoding and decoding method of the five-order RLL(1,4) modulation code provided by the present application to obtain user data.

[0047] According to still another aspect of the present application, there is provided an optical storage system, comprising: an optical storage medium, and the read-write device of the optical storage system provided by the present application.

[0048] In general, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0049] (1) The encoding and decoding method of the fifth-order RLL (1,4) modulation code provided by the present invention realizes the fifth-order run-length limited modulation coding, wherein the minimum run and the maximum run are 2 and 5 respectively, the corresponding density coefficient density value is 2.68, and the theoretical capacity value is 1.34. Compared with the fourth-order RLL (1,7) code and the fourth-order RLL (1,3) code, the density coefficient and the capacity are improved. The present invention encodes 5-bit source data into 4-bit channel code elements, and its coding efficiency is 5 / 4=1.25. Compared with the fourth-order RLL (1,7) code and the fourth-order RLL (1,3) code, the coding efficiency is significantly improved. In addition, after the encoding and decoding process determines the corresponding channel code elements or source data according to the encoding and decoding table, it can be directly spliced ​​in sequence without involving the processing of additional information bits, which effectively reduces the complexity of encoding and decoding. In general, the present invention effectively improves the encoding efficiency without affecting the density coefficient and capacity of the optical storage system or the encoding and decoding complexity, thereby improving the storage efficiency of the optical storage system.

[0050] (2) The reading and writing method of the optical storage system provided by the present invention is implemented based on the encoding and decoding method of the fifth-order RLL (1,4) modulation code provided by the present invention. Due to the high encoding and decoding efficiency, the reading and writing performance is improved.

[0051] (3) The reading and writing method of the optical storage system provided by the present invention, in its preferred embodiment, in the read operation, before the NRZ sequence read from the optical storage medium is NRZ inverse modulated, the error waveform that does not comply with the run length constraint in the NRZ sequence to be decoded is first detected and corrected to make the NRZ sequence comply with the run length constraint; thereby, the bit error rate caused by random noise can be effectively reduced without relying on additional information bits. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A one-step state transition diagram of a fifth-order RLL (1,4) modulation code provided in an embodiment of the present invention;

[0053] Figure 2 A four-step state transition diagram of a fifth-order RLL (1,4) modulation code provided in an embodiment of the present invention;

[0054] Figure 3 A four-step state transition diagram of a fifth-order RLL (1,4) modulation code after state segmentation and merging is provided for an embodiment of the present invention;

[0055] Figure 4 Performance analysis of fifth-order run-length limited codes under different parameters provided by the embodiment of the present invention;

[0056] Figure 5A coding and decoding method schematic diagram of the five-order RLL(1,4) modulation code provided for the embodiment of the present application is shown in the figure;

[0057] Figure 6 A read-write method schematic diagram of the optical storage system provided for the embodiment of the present application is shown in the figure;

[0058] Figure 7 A schematic diagram of the existing optical storage system is shown in the figure;

[0059] Figure 8 An NZR modulation schematic diagram provided for the embodiment of the present application is shown in the figure;

[0060] Figure 9 A five-order RLL(1,4) modulation code experimental design diagram provided for the embodiment of the present application is shown in the figure;

[0061] Figure 10 A five-order RLL(1,4) modulation code noise adding experimental diagram provided for the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the present application more clear and understandable, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0063] In the present application, the terms "first", "second" and the like (if any) in the present application and the drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0064] In view of the problems of low coding efficiency and limited capacity improvement of the existing multi-order run-length limited modulation coding, the present application proposes a coding and decoding method and a read-write method of five-order RLL(1,4) modulation code, and the overall idea is to design a coding and decoding rule which can be actually applied to an optical storage system, and the coding and decoding rule can significantly improve the capacity and coding efficiency of the optical storage system with lower complexity.

[0065] Before explaining the technical scheme of the present application in detail, the design idea for determining the coding and decoding rule is introduced first.

[0066] The run-length limited coding RLL(d,k) is a widely used modulation code in optical storage, wherein the parameters d and k represent the following meanings: there are at least d "0"s between two non-zero elements, and at most k "0"s, i.e. the minimum run and the maximum run. The parameter d limits the highest jump frame rate of the signal, and controls the interference between adjacent jumps; the parameter k controls the lowest jump frequency, and ensures the correct recovery in the reference formula.

[0067] Compared with EFM, EFMplus and 17PP encoding, the multi-order run-length limited encoding has a higher code rate, thus being able to improve the capacity of the optical storage system. At present, the modulation order of the run-length limited encoding widely used in the optical storage system is two, i.e. each code symbol obtained by the encoding is a binary number, taking the value of "0" or "1", and the improvement of the system capacity is limited. The use of the run-length limited encoding of a higher order can theoretically more effectively improve the system capacity, but the pressure on the signal detection mechanism will also be greater. The order, parameters (d, k) of the run-length limited encoding are different, and the density coefficient and the capacity will be different. Meanwhile, there is a certain constraint relationship between the code rate and the capacity, and the code rate and the encoding complexity will also affect each other. The existing multi-order run-length limited encoding scheme, while pursuing the capacity improvement, often ignores the multi-order nature of the material itself, cannot guarantee the reliable storage of information, or greatly increases the complexity of the encoding and decoding, thus, limited by the multi-order nature of the material, the modulation means and the signal detection mechanism, the existing multi-order run-length limited modulation encoding cannot be practically applied to the optical storage system.

[0068] Table 1 density coefficients of different encoding schemes

[0069]

[0070] As shown in Table 1, for different values of the order M and the parameters (d, k), the density coefficients that the corresponding encoding schemes can theoretically achieve, i.e. the amount of information stored per bit.

[0071] It is easy to understand that, since the number of information bits can only be an integer in the actual encoding process, the density coefficients of different encoding schemes in the actual application can only be obtained by rounding down the theoretical values shown in Table 1.

[0072] Increasing the encoding order can improve the storage capacity. In order to effectively improve the storage capacity without affecting the reliability of data storage, the order of the run-length limited encoding designed by the present application is 5. Under the condition of the order of 5, in order to obtain a larger density coefficient, d = 1 is taken, and the remaining parameters are analyzed, as shown in Table 2. Figure 4 Meanwhile, the encoding code rate, the encoding efficiency and the encoding and decoding complexity are taken into account, d = 1 and k = 4 are taken. The theoretical maximum value of the code rate is the capacity C(M, d, k) of the modulation encoding, and the calculation formula is:

[0073] C(M, d, k) = log2λ (1)

[0074] Wherein, λ is the eigenvalue of the following characteristic equation:

[0075] Z k+2 -Z k+1 -(M-1)Zk-d+1 +M-1=0 (2)

[0076] According to the values of d and k, a one-step state transition diagram of the modulation code can be drawn, as shown in the figure. Figure 1 In the run-length limited code, a (k+1) x (k+1) connection matrix T is usually used to represent the relationship between states, and an element t ij in the connection matrix T represents the total number of paths from state i to state j after one-step transition. Figure 1 According to the one-step state transition diagram shown in the figure, a one-step state transition matrix T of the 5-order RLL(1, 4) code can be constructed:

[0077]

[0078] Theoretical analysis shows that the maximum eigenvalue of the connection matrix T is the maximum real root of equation (2), that is, the value of λ in equation (1). According to the calculation, the capacity of the 5-order RLL(1, 4) code is C=1.343714136717185.

[0079] The code rate R of the multi-order run-length limited coding is m / n < C, where m and n respectively represent the number of bits of the source data and the channel symbols. The capacity of the 5-order RLL(1, 4) code determined in the present application is C=1.343714136717185. In order to obtain higher coding efficiency and at the same time obtain as low as possible coding and decoding complexity, in the present application, a code rate is selected for coding, that is, 5-bit source data is converted into 4-bit 5-order modulation data (channel symbols) through modulation coding. In the present application, the number of bits of the channel symbols is n=4, and therefore, the one-step state transition diagram shown in the figure needs to be derived into a four-step state transition diagram, as shown in the figure. Figure 2 4 According to theoretical analysis, the four-step state transition matrix T ij is t ij , where t 4 represents the total number of paths from state i to state j after four-step transition. The four-step state transition matrix T 4 is:

[0080]

[0081] In order to convert 5-bit source data into 4-bit channel symbols, the sum of each row in the four-step state transition matrix T 5 must be greater than or equal to 2 4 =32, but the sum of the first row is 29, which does not meet the coding requirement. According to the state splitting and merging theory, a state is deleted, and the corresponding row and column in the corresponding four-step state transition matrix are also deleted. After the first row and the first column of the four-step state transition matrix are deleted, the code table cannot be constructed. ​

[0082] In order to implement the corresponding coding scheme, the present invention proposes to use a slider grouping algorithm to calculate the four-step state transfer matrix T 4 The eigenvectors of 4 *v≥2 5 *v holds. One of the eigenvalue vectors that satisfies the inequality is v = [12 1 1 0] T (T stands for transpose). The elements in the eigenvalue vector v represent the actual number of states corresponding to the original state during encoding, and also indicate whether the original state should be split, retained, or discarded. The first, third, and fourth elements are 1, indicating that states 1, 3, and 4 are retained; the second element is 2, indicating that state 2 is split into two states; and the fifth element is 0, indicating that state 5 is discarded. Because state 2 is split into two states and state 5 is discarded, the corresponding elements in the four-step state transition matrix change accordingly as follows.

[0083]

[0084] The elements represented in the matrix also change from the n-step state transition path between states 1, 2, 3, 4, and 5 to 1, 2 1 , 2 2 , n-step state transition path between states 3 and 4, state 2 1 and 2 2 Represents two states split from the original state 2.

[0085] The code rate determined by the present invention is The fourth-order RLL (1, 4) code, in which the 5-bit source data has a total of 2 5 =32, because after state segmentation and discarding, the sum of each row in the new four-step state transfer matrix is ​​greater than or equal to 32, which meets the coding requirements. At this time, encoding can be performed according to the traditional coding scheme, thereby designing the encoding and decoding table of the 5th-order RLL (1,4) code.

[0086] Based on the above state splitting operation, the four four-step state transition paths from state 1 to state 2 can be used twice, so the total number of output paths for state 1 is 33, which is greater than 32 and meets the encoding requirements. Figure 2 The fifth-order RLL (1,4) code has four-step state transitions. At this time, state 2 is divided into 2 1 , 2 2 Therefore, the output path of state 2 needs to meet 2*32=64 kinds of source data encoding into different state transition paths, and the total number of output paths of state 2 is exactly 64 to meet the encoding requirements. After discarding state 5, the encoding requirements are still met. 2 The three states 3, 4 and 5 are merged, so the four-step state transition diagram of the three states is obtained as follows: Figure 3 shown.

[0087] The state 1 output path is exactly 32, after encoding state 1, each path represents the transition between states, and transitions to state 2 1 and state 2 2 , 3 and 4, and then encodes according to the output path of the current state. After state merging, Figure 3 The four-step state transition diagram shown contains 3 states, in the following embodiment, state 1 (i.e. the starting state) is recorded as state A, state 2 1 is recorded as state B, and the state after merging states 2 2 , 3 and 4 is recorded as state C.

[0088] The application merges optional encoding states in the case of determining encoding parameters, and retains states that cannot be state split and state merged, finally retains three states A, B and C, and performs multi-state encoding on the retained states, and needs to establish 2 5 = 32 mapping relationships in each state, a total of 96 mapping relationships.

[0089] It should be noted that since the modulation code used by the application is 5th order, each code symbol is a 5-digit number, and in the state transition diagram, only "0" and non-zero are distinguished, so in the state transition path, the value of the non-zero element is 1-4, for example, "0004" represents four paths 0001-0004; and for example, "0404" represents 16 paths 0101-0104, 0201-0204, 0301-0304, 0401-0404.

[0090] On the basis of the above analysis, first, the output path of state A is encoded, and under state A, the output path is 000X, 00X0, 0X00, 0X0X, wherein 00X0 can be used twice, and X takes values 1-4, a total of 32, which exactly meets the encoding requirements, and the next group of mapping relationship corresponding to 0X00, 000X, 00X0, 0X0X is state C, state A, state B and state A respectively. Alternatively, in the following embodiment, the encoding scheme of state A is: 00000-00011 is mapped to 0001-0004, 00100-00111 is mapped to 0010, 0020, 0030, 0040, 01000-01111 is mapped to 0100, 0200, 0300, 0400, 0010, 0020, 0030, 0040, 10000-11111 is mapped to 0101-0404.

[0091] By encoding the state A, the next encoding state of each path is determined, on the basis of which the output paths of state B are encoded. Under state B, the output paths are 000X, 00X0, 0X00, X000, X0X0, totally 32, which just meet the encoding requirement, and the next group of mapping relation corresponding to 000X, 00X0, 0X00, X000, X0X0 is state A, state B, state C, state C and state B respectively. In the following embodiment, the encoding scheme of state B is: 00000-00011 is mapped to 0001-0004, 00100-00111 is mapped to 0010, 0020, 0030, 0040, 01000-01111 is mapped to 0100, 0200, 0300, 0400, 1000, 2000, 3000, 4000, 10000-11111 is mapped to 1010-4040.

[0092] After the encoding of state A and state B is determined, the output paths of state C are further encoded. Under state C, the output paths are X00X, 0X0X, totally 32, and the encoding and decoding state of the next group of mapping relation corresponding to X00X, 0X0X is state A. In the following embodiment, the encoding scheme of state C is: 00000-01111 is mapped to 1001-4004 in turn; 10000-11111 is mapped to 0101-0404 in turn.

[0093] The mapping relation is shown in Table 2 specifically, wherein NS represents the encoding and decoding state corresponding to the next group of mapping relation. It should be explained that the mapping relation between the source data and the channel symbol shown in Table 2 is only the preferred embodiment of the present application, and should not be understood as the unique limitation of the present application. The one-to-one corresponding relation between the 32 kinds of source data and the 32 kinds of channel symbols selected from the channel symbols of the three states can be used in the present application.

[0094] Table 2 Mapping relation between source data and channel symbol

[0095]

[0096]

[0097] Based on the corresponding relation shown in Table 2, the encoding and decoding table can be established, which is used for data encoding and decoding in the optical storage system. The element in the encoding and decoding table is expressed in the format of {(D, S), NS}, wherein D represents the source data, S represents the mapped channel symbol, and NS represents the encoding and decoding state corresponding to the next group of mapping relation, and state A, state B and state C are marked as A, B and C respectively, so that:

[0098] In state A, the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols, and the coding state of the next group of mapping relationships of each group of mapping relationships are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 0010), C}, {(01101, 0020), C}, {(01110, 0030), C}, {(01111, 0040), C}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010, 0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110, 0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010, 0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110, 0403), A}, {(11111, 0404), A};

[0099] In state B, the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols, and the coding state of the next group of mapping relationships of each group of mapping relationships are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 1000), C}, {(01101, 2000), C}, {(01110, 3000), C}, {(01111, 4000), C}, {(10000, 1010), B}, {(10001, 1020), B}, {(10010, 1030), B}, {(10011, 1040), B}, {(10100, 2010), B}, {(10101, 2020), B}, {(10110, 2030), B}, {(10111, 2040), B}, {(11000, 3010), B}, {(11001, 3020), B}, {(11010, 3030), B}, {(11011, 3040), B}, {(11100, 4010), B}, {(11101, 4020), B}, {(11110, 4030), B}, {(11111, 4040), B};

[0100] The mapping relationship between 32 5-bit source data and 32 4-bit channel symbols in state C and the coding state of the next group of mapping relationship are: {(00000, 1001), A}, {(00001, 1002), A}, {(00010, 1003), A}, {(00011, 1004), A}, {(00100, 2001), A}, {(00101, 2002), A}, {(00110, 2003), A}, {(00111, 2004), A}, {(01000, 3001), A}, {(01001, 3002), A}, {(01010, 3003), A}, {(01011, 3004), A}, {(01100, 0010), A}, {(01101, 0020), A}, {(01110, 0030), A}, {(01111, 0040), A}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010, 0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110, 0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010, 0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110, 0403), A}, {(11111, 0404), A}.

[0101] In the coding process, the first group of source data or channel symbols in the coding state is coded according to the coding table state A, and the coding state corresponding to the next group of data in the coding table is specified. This scheme in which multiple states are related to each other is called state correlation.

[0102] In the present application, the path that does not meet the d, k run length restriction has been removed in the four-step state transition diagram, so that the channel symbols obtained by coding based on the established mapping relationship can meet the d, k run length restriction without additional information bits after being spliced in sequence.

[0103] The above five-order RLL(1, 4) code designed by the application has a minimum run length of 2 and a maximum run length of 5, a corresponding density coefficient density value of 2.68742827343437, and a capacity theoretical value of 1.343714136717185, and the density coefficient and the capacity are considered, the capacity of the optical storage system is effectively improved without changing the optical parameters of the optical storage system, meanwhile, the application encodes 5-bit source data into 4-bit channel symbols, the encoding efficiency is 5 / 4, the encoding efficiency is effectively improved, and the encoding and decoding process does not involve the processing of additional information bits, and the encoding complexity is not high, therefore, the application can consider the density sparsity, the capacity, the encoding efficiency and the encoding complexity under the limitation of the material multi-order and the modulation method, and can be practically applied to the optical storage system, and the capacity of the optical storage system is improved.

[0104] Without loss of generality, the following embodiments are implemented on the basis of the mapping relationship shown in Table 2. The following is an embodiment.

[0105] Embodiment 1:

[0106] A five-order RLL(1, 4) modulation code encoding and decoding method, as shown in Figure 5 , comprising an encoding step and a decoding step;

[0107] The encoding step comprises: dividing user data into source data with a length of 5 bits to obtain a source data sequence; setting the encoding and decoding state of the first source data to state A, then traversing the source data sequence, for each traversed source data, converting it into a 4-bit channel symbol according to a pre-established encoding and decoding table, and determining the encoding and decoding state corresponding to the next traversed source data; after the traversal is completed, splicing the channel symbols in sequence to obtain an RLL sequence;

[0108] The decoding step comprises: dividing the RLL sequence to be decoded into 4-bit channel symbols to obtain a channel symbol sequence; setting the encoding and decoding state of the first channel code to state A, then traversing the channel symbol sequence, for each traversed channel symbol, converting it into 5-bit source data according to the encoding and decoding table, and determining the encoding and decoding state corresponding to the next traversed channel symbol; after the traversal is completed, splicing the source data in sequence to obtain user data;

[0109] The encoding and decoding table is used to record the mapping relationship between 32 kinds of 5-bit source data and 32 kinds of 4-bit channel symbols under different encoding and decoding states, and the encoding and decoding state of the next group of mapping relationships of each group of mapping relationships, as shown in Table 2.

[0110] In summary, the coding and decoding method of the five-order RLL(1, 4) modulation code provided by the embodiment realizes five-order run-length limited modulation coding, in which the minimum run length and the maximum run length are 2 and 5 respectively, the corresponding density coefficient density value is 2.68, and the capacity theoretical value is 1.34. Compared with the four-order RLL(1, 7) code and the four-order RLL(1, 3) code, the density coefficient and the capacity are improved. The embodiment encodes 5-bit source data into 4-bit channel symbols, and the encoding efficiency is 5 / 4=1.25. Compared with the four-order RLL(1, 7) code and the four-order RLL(1, 3) code, the encoding efficiency is obviously improved. In the coding and decoding process, the corresponding channel symbols or source data are determined according to the coding and decoding table, and then directly spliced in sequence, without involving the processing of additional information bits, thereby effectively reducing the complexity of coding and decoding.

[0111] It is easy to understand that if the mapping relationship between the source data and the channel symbols changes, or the selected channel symbols in each state change, the conversion between the source data and the channel symbols in the coding and decoding process can be completed according to the new coding and decoding table, and the coding and decoding state of the next group of mapping relationship can be determined.

[0112] Embodiment 2:

[0113] An optical storage controller, comprising:

[0114] A computer readable storage medium for storing a computer program;

[0115] and a processor for reading the computer program stored in the computer readable storage medium, and executing the coding and decoding method of the five-order RLL(1, 4) modulation code provided in the above embodiment 1.

[0116] Embodiment 3:

[0117] A read-write method of an optical storage system, as shown in Figure 6 , comprising: a writing operation and a reading operation;

[0118] The writing operation comprises:

[0119] The user data is encoded into an RLL sequence by using the encoding step of the coding and decoding method of the five-order RLL(1, 4) modulation code provided in the above embodiment 1;

[0120] The RLL sequence obtained by encoding is subjected to NRZ modulation to obtain an NRZ sequence to be written;

[0121] The NRZ sequence to be written is written into the optical storage medium of the optical storage system;

[0122] The reading operation comprises:

[0123] The target data is read from the optical storage medium to obtain an NRZ sequence;

[0124] NRZ inverse modulation is performed on the NRZ sequence read from the optical storage medium to obtain the RLL sequence;

[0125] The RLL sequence obtained by inverse modulation is demodulated by using the decoding step of the encoding and decoding method of the five-order RLL (1, 4) modulation code provided in Embodiment 1 to obtain user data.

[0126] In practical applications, a multi-order optical storage system is as shown in FIG. 1. Figure 7 During the writing process, the RLL sequence obtained by encoding cannot be directly written into the optical storage medium and needs to be modulated into a corresponding write-in waveform. Since the run-length limited encoding adopted in the present embodiment is five-order, the modulation manner of the RLL sequence in the present embodiment is NRZ (Non-Return to Zero) modulation. Figure 8 FIG. 2 shows an example of NRZ modulation. Correspondingly, the signal read from the optical disc needs to be subjected to NRZ inverse modulation, which is the inverse process of NRZ modulation.

[0127] In practical applications, a multi-order optical storage system not only generates adjacent channel crosstalk caused by narrow channel spacing and inter-symbol interference caused by increased bit density, but is also more susceptible to jitter or scratches and is prone to burst errors. At this time, the signal read from the optical disc first needs to be subjected to PRML signal detection, and the signal subjected to identification is given to the modulation and encoding system, and only random noise exists in the signal. Random noise changes the signal waveform and generates a waveform that does not satisfy the run-length constraint. If direct NRZ inverse modulation is performed, a long string of continuous errors can be caused, correct demodulation cannot be performed, the bit error rate is excessively high, and the performance of the error correction module in the optical disc data channel system is further affected.

[0128] In order to reduce the bit error rate, as a preferred embodiment, the present embodiment further includes, before the NRZ inverse modulation is performed on the NRZ sequence read from the optical storage medium, detecting and correcting error waveforms in the NRZ sequence to be decoded that do not satisfy the run-length constraint, so that the NRZ sequence satisfies the run-length constraint.

[0129] The present embodiment implements a five-order RLL (1, 4) code, and the minimum run-length and the maximum run-length are 2 and 5, respectively. Correspondingly, the run-length constraint is that the number of continuous and identical signals is greater than or equal to 2 and less than or equal to 5, which can be represented by a symbol as run constraint (2T-5T), where “T” represents a detection period.

[0130] The embodiment specifically adopts a sliding window detection method to detect the NRZ sequence read from the optical disc. In the sliding window, it is detected whether the signal meets the run constraint (2T-5T). In the detection process, the signal sequence meeting the run constraint is outputted by sliding the sliding window, and the same number of undetected signals is supplemented. If the signal not meeting the run constraint is detected, the signal is corrected in combination with the run of the front and rear signals. Specifically, the error waveform not meeting the run length constraint in the NRZ sequence to be decoded is detected and corrected, including the following steps:

[0131] S0: setting a sliding window with a length of N at the head of the NRZ sequence;

[0132] S1: dividing the signal in the sliding window into signal groups; each signal group is composed of a single signal or a plurality of same and continuous signals, and adjacent signal groups contain different code symbol;

[0133] S2: counting the number of signals contained in each signal group to detect whether each signal group meets the run length constraint;

[0134] S3: if the signal group G h at the head of the sliding window meets the run length constraint, sliding the sliding window to the rear to the signal group G h removed, and then returning to step S5; otherwise, returning to step S4;

[0135] S4: if the number of signals contained in the signal group G h is less than 2, correcting the signal after the signal group G h to the signal in the signal group G h to update the signal group G h , sliding the sliding window to the rear to the signal group G h removed, and then returning to step S5; if the number of signals contained in the signal group G h is greater than 5, correcting the signal from the 6th to the end in the signal group G h to the signal after the signal group G h to update the signal group G h , sliding the sliding window to the rear to the signal group G h removed, and then returning to step S5;

[0136] S5: if there is still a signal in the sliding window, returning to step S1; otherwise, the correction is ended;

[0137] In the embodiment, the symbol length is 4T, the run constraint is (2T-5T), the change that cannot be covered in the run constraint by a single symbol length needs at least two symbol lengths to distinguish all changes, and therefore the length N of the sliding window needs to be greater than or equal to 8; experiments show that when the length of the sliding window is set to 10, the error waveform that does not conform to the run length constraint can be more efficiently detected, and therefore, as a preferred embodiment, the length of the sliding window in the embodiment is 10.

[0138] The detection and correction process is further explained below in combination with a specific example. If the signal in a sliding window position is 1022223244, it can be divided into six signal groups: the first group is "1", containing 1 signal, which does not conform to the run length constraint; the second group is "0", containing 1 signal, which does not conform to the run length constraint; the third group is "2222", containing 4 signals, which conforms to the run length constraint; the fourth group is "3", containing 1 signal, which does not conform to the run length constraint; the fifth group is "2", containing 1 signal, which does not conform to the run length constraint; and the sixth group is "44", containing 2 signals, which conforms to the run length constraint.

[0139] The first two groups of signals are corrected to "11", and the fourth and fifth groups of signals are corrected to "33", and finally the signal in the sliding window is corrected to 1122223344.

[0140] In general, the embodiment detects the RLL sequence to be decoded based on the minimum run length and the maximum run length, corrects the signal that does not conform to the run constraint to the signal that conforms to the run constraint, and after demodulation, can effectively reduce the bit error rate caused by noise. Figure 9 The figure shows a five-order RLL (1, 4) modulation code noise experiment design provided by the embodiment, and random errors, burst errors, and multi-segment burst errors are added to the data read from the optical disc to simulate the situation of fingerprints and scratches encountered during actual reading of the optical disc. Figure 10 The figure shows a five-order RLL (1, 4) modulation code noise experiment provided by the embodiment, Figure 10The results show that when the added noise is 0 (i.e. not affected by noise), the source data before and after demodulation remains completely consistent, proving the logical correctness of the fifth-order RLL (1,4) modulation code. With the increase of noise, the bit error rate after demodulation also increases, but the bit error rate is always lower than the original bit error rate, proving that the embodiment effectively reduces the bit error rate caused by random noise and burst noise after demodulation, and can effectively control the error propagation within a single code word. After adding multiple burst errors, the bit error rate after demodulation is significantly lower than the bit error rate before demodulation. In subsequent analysis, it is found that the bit error rate caused by multiple burst errors is corrected after being detected by the sliding window detection mechanism, thereby obtaining the experimental results of significantly reducing the bit error rate. In summary, in the face of various error types, the embodiment based on the fifth-order RLL (1,4) modulation code can effectively control the error propagation within a single code word and effectively reduce the bit error rate, thereby reducing the pressure on the subsequent error correction module.

[0141] Embodiment 4:

[0142] A read-write device of an optical storage system, comprising: a write module and a read module;

[0143] The write module comprises:

[0144] An encoding unit configured to encode user data into an RLL sequence by using the encoding step of the encoding and decoding method of the fifth-order RLL (1,4) modulation code provided in Embodiment 1;

[0145] A modulation unit configured to perform NRZ modulation on the RLL sequence obtained by encoding to obtain an NRZ sequence to be written;

[0146] and a writing unit configured to write the NRZ sequence to be written into an optical storage medium of an optical storage system;

[0147] The read module comprises:

[0148] A reading unit configured to read target data from the optical storage medium to obtain an NRZ sequence;

[0149] An inverse modulation unit configured to perform NRZ inverse modulation on the NRZ sequence read from the optical storage medium to obtain an RLL sequence;

[0150] and a decoding unit configured to demodulate the RLL sequence obtained by inverse modulation by using the decoding step of the encoding and decoding method of the fifth-order RLL (1,4) modulation code provided in Embodiment 1 to obtain user data.

[0151] Embodiment 5:

[0152] An optical storage system, comprising: an optical storage medium, and a read-write device of an optical storage system provided in Embodiment 4.

[0153] It is to be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the application should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A coding and decoding method for a fifth-order RLL (1, 4) modulation code, characterized in that: include: Encoding step and decoding step; The encoding step includes: dividing user data into source data of 5 bits in length to obtain a source data sequence; after setting the encoding / decoding state of the first source data to state A, traversing the source data sequence, converting each traversed source data into a 4-bit channel symbol according to a pre-established encoding / decoding table, and determining the encoding / decoding state corresponding to the next traversed source data; after the traversal is completed, splicing the channel symbols in sequence to obtain an RLL sequence; The decoding step includes: dividing the RLL sequence to be decoded into 4-bit channel symbols to obtain a channel symbol sequence; after setting the encoding and decoding state of the first channel code to state A, traversing the channel symbol sequence, for each traversed channel symbol, converting it into 5-bit source data according to the encoding and decoding table, and determining the encoding and decoding state corresponding to the next traversed channel symbol; after the traversal is completed, splicing the source data in sequence to obtain user data; The codec table is used to record the mapping relationships between 32 types of 5-bit source data and 32 types of 4-bit channel code elements under different codec states, as well as the codec states of the next group of mapping relationships of each group of mapping relationships; the different codec states are state A, state B, and state C; in state A, the 32 types of 4-bit channel code elements are 32 of 000X, 00X0, 0X00, and 0X0X, and the codec states of the next group of mapping relationships corresponding to the channel code elements 000X, 00X0, 0X00, and 0X0X are state A, state B, state C, and state A, respectively. ; In state B, the 32 types of 4-bit channel code elements are 32 of 000X, 00X0, 0X00, X000, and X0X0, and the encoding and decoding states of the next set of mapping relationships corresponding to the channel code elements 000X, 00X0, 0X00, X000, and X0X0 are state A, state B, state C, state C, and state B respectively; in state C, the 32 types of 4-bit channel code elements are 32 of X00X and 0X0X, and the encoding and decoding states of the next set of mapping relationships corresponding to the channel code elements X00X and 0X0X are all state A; the value of X is 1 to 4.

2. The encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1, wherein: The elements in the codec table are represented in the format of {(D, S), NS}, where D represents the source data, S represents the mapped channel symbol, and NS represents the codec state corresponding to the next set of mapping relationships. State A, state B, and state C are denoted as A, B, and C, respectively. Then: In state A, the mapping relationships between 32 types of 5-bit source data and 32 types of 4-bit channel codewords, as well as the encoding and decoding states of the next set of mapping relationships in each mapping relationship are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 0010), C}, {(01101, 0020), C}, {(01110,0030), C}, {(01111, 0040), C}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010,0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110,0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010,0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110,0403), A}, {(11111, 0404), A}; In state B, the mapping relationships between 32 types of 5-bit source data and 32 types of 4-bit channel codewords, as well as the encoding and decoding states of the next set of mapping relationships in each mapping relationship are: {(00000, 0001), A}, {(00001, 0002), A}, {(00010, 0003), A}, {(00011, 0004), A}, {(00100, 0010), B}, {(00101, 0020), B}, {(00110, 0030), B}, {(00111, 0040), B}, {(01000, 0100), C}, {(01001, 0200), C}, {(01010, 0300), C}, {(01011, 0400), C}, {(01100, 1000), C}, {(01101, 2000), C}, {(01110,3000), C}, {(01111, 4000), C}, {(10000, 1010), B}, {(10001, 1020), B}, {(10010,1030), B}, {(10011, 1040), B}, {(10100, 2010), B}, {(10101, 2020), B}, {(10110,2030), B}, {(10111, 2040), B}, {(11000, 3010), B}, {(11001, 3020), B}, {(11010,3030), B}, {(11011, 3040), B}, {(11100, 4010), B}, {(11101, 4020), B}, {(11110,4030), B}, {(11111, 4040), B}; In state C, the mapping relationships between the 32 types of 5-bit source data and the 32 types of 4-bit channel codewords, as well as the encoding and decoding states of the next set of mapping relationships of each mapping relationship are: {(00000, 1001), A}, {(00001, 1002), A}, {(00010,1003), A}, {(00011, 1004), A}, {(00100, 2001), A}, {(00101, 2002), A}, {(00110,2003), A}, {(00111, 2004), A}, {(01000, 3001), A}, {(01001, 3002), A}, {(01010,3003), A}, {(01011, 3004), A}, {(01100, 0010), A}, {(01101, 0020), A}, {(01110,0030), A}, {(01111, 0040), A}, {(10000, 0101), A}, {(10001, 0102), A}, {(10010,0103), A}, {(10011, 0104), A}, {(10100, 0201), A}, {(10101, 0202), A}, {(10110,0203), A}, {(10111, 0204), A}, {(11000, 0301), A}, {(11001, 0302), A}, {(11010,0303), A}, {(11011, 0304), A}, {(11100, 0401), A}, {(11101, 0402), A}, {(11110,0403), A}, {(11111, 0404), A}.

3. An optical storage controller, characterized in that: include: a computer-readable storage medium for storing a computer program; and a processor, configured to read the computer program stored in the computer-readable storage medium and execute the encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1 or 2.

4. A reading and writing method for an optical storage system, characterized in that: include: Write operation and read operation; The writing operation includes: Encoding the user data into an RLL sequence using the encoding step of the encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1 or 2; Perform NRZ modulation on the RLL sequence obtained by encoding to obtain the NRZ sequence to be written; Writing the NRZ sequence to be written into the optical storage medium of the optical storage system; The read operation includes: Read target data from the optical storage medium to obtain an NRZ sequence; performing NRZ inverse modulation on the NRZ sequence read from the optical storage medium to obtain an RLL sequence; The decoding step of the encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1 or 2 demodulates the RLL sequence obtained by inverse modulation to obtain user data.

5. The reading and writing method of the optical storage system according to claim 4, wherein: In the read operation, before performing NRZ inverse modulation on the NRZ sequence read from the optical storage medium, the method further includes: detecting an erroneous waveform in the NRZ sequence to be decoded that does not comply with the run length constraint and correcting the waveform so that the NRZ sequence complies with the run length constraint; The run length constraint is that the number of consecutive and identical signals is greater than or equal to 2 and less than or equal to 5.

6. The reading and writing method of the optical storage system according to claim 5, wherein: Detecting and correcting an erroneous waveform that does not conform to the run length constraint in the NRZ sequence to be decoded includes the following steps: S0: Set the length at the head of the NRZ sequence to N Sliding window; S1: Divide the signals in the sliding window into signal groups; each signal group consists of a single signal, or consists of multiple identical and continuous signals, and adjacent signal groups contain different signals; S2: Counting the number of signals contained in each signal group to detect whether each signal group complies with the run length constraint; S3: If the signal group at the head of the sliding window G h If the run length constraint is met, the sliding window is moved backward to the signal group G h Remove, and then go to step S5; Otherwise, go to step S4; S4: If the signal group G h If the number of signals included is less than 2, the signal group G h The last signal is corrected to signal group G h Signals within to update the signal group G h , so that the sliding window slides back to the signal group G h Move out, then go to step S5; if the signal group G h If the number of signals included is greater than 5, the signal group G h The signals from the 6th to the end of the signal are corrected into signal group G h The latter signal of the signal group to update G h , so that the sliding window slides back to the signal group G h Remove, and then go to step S5; S5: If there is still a signal in the sliding window, go to step S1; otherwise, the correction ends; in, N ≥8.

7. The reading and writing method of the optical storage system according to claim 6, wherein: N =10。 8. A read / write device for an optical storage system, characterized in that: include: Writer module and reader module; The writing module includes: an encoding unit, configured to encode user data into an RLL sequence using the encoding step of the encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1 or 2; A modulation unit, configured to perform NRZ modulation on the RLL sequence obtained by encoding to obtain an NRZ sequence to be written; and a writing unit, configured to write the NRZ sequence to be written into the optical storage medium of the optical storage system; The reading module includes: a reading unit, configured to read target data from the optical storage medium to obtain an NRZ sequence; an inverse modulation unit, configured to perform NRZ inverse modulation on the NRZ sequence read from the optical storage medium to obtain an RLL sequence; and a decoding unit for demodulating the RLL sequence obtained by inverse modulation using the decoding step of the encoding and decoding method of the fifth-order RLL (1, 4) modulation code according to claim 1 or 2 to obtain user data.

9. An optical storage system, characterized in that: include: An optical storage medium, and a reading and writing device of the optical storage system according to claim 8.

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