Encoding, decoding, reading and writing methods of fourth-order RLL (1,7) modulation code

Abstract

The present invention discloses a coding and decoding method and a reading and writing method of a fourth-order RLL (1,7) modulation code, which belongs to the field of optical storage technology, comprising: a coding step: dividing user data into 6-bit source data, converting each source data into a 5-bit channel code element according to a coding and decoding table, splicing them in sequence, inserting a merging bit between two adjacent channel code elements to obtain an RLL sequence; a decoding step: removing a merging bit every 5 bits of the RLL sequence to obtain a channel code element, and splicing each signal element according to the coding and decoding table. Channel symbols are converted into 6-bit source data, and the source data are sequentially concatenated to obtain user data. A codec table records the correspondence between 64 types of 6-bit source data and 64 types of 5-bit channel symbols. The channel symbols are 64 of 0000X, 00X0X, 0X00X, X000X, X0X0X, 000X0, 0X0X0, X00X0, 00X00, X0X00, 0X000, and X0000. X ranges from 1 to 3. The present invention can significantly increase the capacity of an optical storage system without changing optical parameters.

Description

Technical Field

[0001] The present invention belongs to the field of optical storage technology, and more specifically, relates to a coding and decoding method and a reading and writing method of a fourth-order RLL (1,7) modulation code. Background Art

[0002] Optical storage technology is widely used for massive cold data storage due to its advantages, including long shelf life, contactless read / write, high security, easy disk replacement, low production cost, and convenient copying and distribution. Traditional optical storage technology stores information based on the interaction between lasers and media, which causes changes in the media's properties. With the advent of the digital age, the demand for information storage continues to grow. It is predicted that the total amount of data generated globally will reach 175 zettabytes (ZB) by 2025. To meet this growing storage demand, increasing the storage capacity of optical storage devices is crucial. Traditional optical storage technology increases storage capacity by reducing the size of the focused laser spot and the recorded symbols on the media. However, due to the optical diffraction limit, increasing the capacity of optical discs using traditional optical storage technology is becoming increasingly difficult.

[0003] In traditional optical storage technology, run-length limited modulation (RLL) has been widely used to ensure signal stability and reliable readout. However, the run-length limited modulation used in more mature products on the market is all second-order, and the symbols obtained by encoding are binary numbers 0 and 1. The material of the optical storage medium itself has multi-order properties and can present different states. Different states can be used to store different information. Compared with traditional second-order run-length limited coding, multi-order run-length limited coding can better utilize the multi-order properties of the material and improve the capacity of the optical storage device. However, blindly increasing the coding order may cause the optical storage medium to be unable to store data stably and reliably. For example, in the patent document with application publication number CN1553450A, an 8-order (1, 2) code is used to convert 3-bit source data into 2-bit code elements. Its theoretical capacity is 1.6083 and the code rate is 3 / 2. The theoretical capacity is relatively high. However, it requires the optical storage medium to present 8 different states accordingly. Due to the limitations of the material itself, the difference between adjacent states is small, errors are prone to occur during the writing and reading process, and the same state is difficult to maintain stably, making it impossible to store data stably and reliably.

[0004] Therefore, due to the limitations of the multi-order nature of the material and the modulation method, the existing multi-order run-length limited modulation coding is still in the theoretical stage and cannot take into account the improvement of the order, capacity and coding complexity, and has certain limitations in practical applications. Summary of the Invention

[0005] In response to the defects of the existing technology and the need for improvement, the present invention provides an encoding and decoding method and a reading and writing method for a fourth-order RLL (1,7) modulation code, the purpose of which is to significantly improve the capacity of the optical storage system without changing the optical parameters.

[0006] To achieve the above object, according to one aspect of the present invention, a coding and decoding method for a fourth-order RLL (1,7) modulation code is provided, comprising: a coding step and a decoding step;

[0007] The encoding step includes: dividing the user data into 6-bit source data, converting each source data into a 5-bit channel symbol according to a pre-established codec table, concatenating the channel symbols in sequence, and inserting a merging bit between two adjacent channel symbols to obtain an RLL sequence;

[0008] The decoding step includes: removing one merging bit every five bits of the RLL sequence to be decoded to obtain a 5-bit channel symbol, converting each channel symbol into a 6-bit source data according to the codec table, and sequentially splicing the source data to obtain user data;

[0009] Among them, the merging bit is used to ensure that there is at least one "0" between any two non-zero elements in the RLL sequence; the codec table is used to record the one-to-one correspondence between 64 types of 6-bit source data and 64 types of 5-bit channel code elements, and the 64 5-bit channel code elements are 0000X, 00X0X, 0X00X, X000X, X0X0X, 000X0, 0X0X0, X00X0, 00X00, X0X00, 0X000, X0000; the value of X is 1 to 3.

[0010] Furthermore, the 64 5-bit channel symbols include: 00X00, 0X0Y0, X0Y0Y, a total of 63 types; and 1 type of 00X0X;

[0011] The value of Y ranges from 0 to 4.

[0012] Furthermore, in the codec table, the one-to-one correspondence between the 6-bit source data and the 5-bit signal code element is as follows:

[0013] 000000 corresponds to one of 00X0X;

[0014] 000001 to 000011 correspond to 00100 to 00300 respectively;

[0015] 000100 to 001111 corresponds to 01000 to 03030;

[0016] 010000~111111 corresponds to 10000~30303 respectively.

[0017] According to another aspect of the present invention, there is provided an optical storage controller, comprising:

[0018] a computer-readable storage medium for storing a computer program;

[0019] and a processor for reading a computer program stored in a computer-readable storage medium and executing the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention.

[0020] According to another method of the present invention, a reading and writing method of an optical storage system is provided, comprising: a writing operation and a reading operation;

[0021] The writing operation includes:

[0022] Encoding the user data into an RLL sequence using the encoding step of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention;

[0023] Perform NZR modulation on the RLL sequence obtained by encoding to obtain the NZR sequence to be written;

[0024] Writing the NZR sequence to be written into the optical storage medium of the optical storage system;

[0025] The read operation includes:

[0026] Read target data from the optical storage medium to obtain an NZR sequence;

[0027] Performing NZR inverse modulation on the NZR sequence read from the optical storage medium to obtain an RLL sequence;

[0028] The decoding step of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention demodulates the RLL sequence obtained by inverse modulation to obtain user data.

[0029] According to another aspect of the present invention, there is provided a read / write device of an optical storage system, comprising: a write module and a read module;

[0030] The writing module includes:

[0031] An encoding unit, configured to encode user data into an RLL sequence using the encoding step of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention;

[0032] A modulation unit, configured to perform NZR modulation on the RLL sequence obtained by encoding to obtain an NZR sequence to be written;

[0033] and a writing unit for writing the NZR sequence to be written into the optical storage medium of the optical storage system;

[0034] Read modules include:

[0035] A reading unit, used for reading target data from an optical storage medium to obtain an NZR sequence;

[0036] an inverse modulation unit, configured to perform NZR inverse modulation on the NZR sequence read from the optical storage medium to obtain an RLL sequence;

[0037] 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 fourth-order RLL (1,7) modulation code provided by the present invention to obtain user data.

[0038] According to another aspect of the present invention, an optical storage system is provided, comprising: an optical storage medium, and a reading and writing device utilizing the optical storage system provided by the present invention.

[0039] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0040] (1) The encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention realizes the fourth-order run-length limited modulation coding, wherein the minimum run and the maximum run are 1 and 7 respectively, the corresponding density coefficient theoretical value is 2.40, and the capacity theoretical value is 1.202, taking into account both the density coefficient and the capacity, and effectively improving the capacity of the optical storage system without changing the optical parameters of the optical storage system. At the same time, the present invention encodes 6-bit source data into 5-bit channel code elements, and its coding efficiency is 6 / 5. The number of corresponding relationships required to be established is 64, and the coding efficiency is high while the coding complexity is not high. In general, the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention can take into account the density coefficient, capacity, coding efficiency and coding complexity under the limitation of the multi-order property of the material and the modulation method, and can be actually applied to the optical storage system to achieve the effect of improving the capacity of the optical storage system.

[0041] (2) In the preferred embodiment of the coding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention, after determining the coding parameters, the optional channel code elements are merged, and finally several channel code elements with specific formats are selected to complete the construction of the coding and decoding table. The selected channel code element formats are 00X00, 0X0Y0, X0Y0Y, and 00X0X. Since the formats of these channel code elements have obvious characteristics, in practical applications, for each channel code element, only 3 code element symbols need to be stored at most, and the channel code element can be determined in combination with the specific format, further reducing the coding complexity.

[0042] (3) In the preferred embodiment of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided by the present invention, the selected channel code elements have a specific format, and in the established correspondence between the source data and the channel code elements, the channel code elements corresponding to 000001 to 111111 are ordered, so that the correspondence between the source data and the channel code elements can be determined more efficiently during the encoding and decoding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A one-step state transition diagram of a 4th-order (1, 7) code provided in an embodiment of the present invention;

[0044] Figure 2 A five-step state transition diagram of a 4th-order (1, 7) code provided in an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of encoding and decoding provided by an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of a reading and writing method of an optical storage system provided by an embodiment of the present invention;

[0047] Figure 5 A schematic diagram of NZR modulation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0049] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0050] In response to the problem that existing multi-order run-length limited modulation coding is limited by the multi-order nature of the material and the modulation method, and cannot be actually applied to optical storage systems to improve the capacity of optical storage systems, the present invention proposes a coding and decoding method and a reading and writing method for a fourth-order RLL (1,7) modulation code. The core of the method is to design a coding and decoding rule that can be actually applied to optical storage systems. The coding and decoding rule can significantly improve the capacity of optical storage systems with lower complexity.

[0051] Before explaining the technical solution of the present invention in detail, the determination of the encoding and decoding rules therein is first introduced.

[0052] Run-length limited coding (RLL(d,k)) is a modulation code widely used in optical storage. The parameters d and k represent the minimum and maximum run lengths, respectively, which define the interval between two non-zero elements: at least d zeros and at most k zeros. The parameter d limits the maximum transition rate of the signal, controlling interference between adjacent transitions; the parameter k controls the minimum transition frequency, ensuring accurate recovery of the reference equation.

[0053] Compared to EFM and EFMplus, multi-level run-length limited coding (MLLC) offers higher bit rates and can therefore increase the capacity of optical storage systems. Currently, the MLLC modulation order widely used in optical storage systems is second-order, meaning each encoded symbol is a binary number, either "0" or "1," resulting in limited improvement in system capacity. Higher-order MLLCs can theoretically improve system capacity more effectively, but different MLLC order and parameters (d, k) will result in different density coefficients and capacities. Furthermore, there are constraints between bit rate and capacity, and between bit rate and coding complexity. Existing MLLC schemes, while pursuing capacity increases, often overlook the inherent multi-order nature of the material, failing to ensure reliable information storage or significantly increasing encoding and decoding complexity. Consequently, due to the limitations of the material multi-order nature and modulation methods, existing MLLC modulation schemes are not practical for optical storage systems.

[0054] Table 1 shows the density coefficients that can be theoretically obtained by the corresponding coding scheme under different values ​​of the order M and the parameters (d, k), that is, the amount of information stored in each bit.

[0055] It is easy to understand that, since the number of information bits can only be integers in the actual coding process, the density coefficients of different coding schemes in practical applications can only be obtained by rounding down the theoretical values ​​shown in Table 1.

[0056] Table 1 Density coefficients of different coding schemes

[0057]

[0058] In order to effectively increase storage capacity without affecting data storage reliability, the run-length limited coding designed in this invention has an order of 4. At the same time, in order to achieve a larger density coefficient while taking into account capacity (the larger the value of d, the larger the density coefficient and the smaller the capacity), d = 1 and k = 7 are set. The theoretical maximum value of the code rate is the modulation coding capacity C(M, d, k), which is calculated as follows:

[0059] C(M, d, k) = log2λ (1)

[0060] where λ is the characteristic root of the following characteristic equation:

[0061] z k+2 -z k+1 -z k+1-d +1=0 (2)

[0062] According to the values ​​of d and k, the one-step transfer state diagram of the modulation code can be drawn, as shown in Figure 1 As shown. The commonly used (k+1)×(k+1) connection matrix T=t ij To express the relationship between states, where t ij represents the total number of paths from state i to state j. Based on the one-step state transition diagram, the one-step state transition matrix T of the 4th-order RLL (1, 7) code can be constructed:

[0063]

[0064] Theoretical analysis shows that the maximum eigenvalue of the connection matrix T is the maximum real root of equation (2), which is also the value of λ in equation (1). According to calculation, the capacity of the 4th-order RLL (1,7) code can be obtained: C = 1.202.

[0065] The code rate of multi-order run-length limited coding is R=m / n<C, where m and n represent the number of bits of source data and channel code elements respectively. The capacity of the 4-order RLL (1,7) code determined by the present invention is C=1.202. In order to obtain higher coding efficiency without significantly increasing the coding complexity, the code rate is selected in the present invention. Encoding is performed, that is, the 6-bit source data is converted into 5-bit 4th-order modulated data through modulation coding. Therefore, it is necessary to derive the one-step state transfer to the five-step state transfer. The number of paths of the five-step state transfer is shown in Table 2.

[0066] Table 2 Five-step state transition table of 4th-order RLL(1,7) code

[0067]

[0068]

[0069] It should be noted that, since the modulation code used in the present invention is 4-order, each code element symbol is a 4-ary number. At the same time, in the five-step state transition diagram, only "0" and non-zero are distinguished. Therefore, in the five-step path in Table 2 above, the value of the non-zero element is 1 to 3. For example, "00003" represents the three paths of 00001 to 00003; for another example, "00303" represents the nine paths of 00101 to 00103, 00201 to 00203, and 00301 to 00303.

[0070] The present invention determines The 4th order RLL (1, 7) code, in which the 6-bit source data has a total of 2 6 =64. If the number of output paths for each state in the five-step state transition table is at least 64, then the codec for a 4th-order RLL (1, 7) code can be directly designed. Both states 0 and 7 have fewer than 64 output paths. Since state 0, as a pivot point in state transitions, cannot be discarded, state 7 is discarded. During the encoding process, 30303, 00303, 30003, 30300, 00003, 00300, and 30000 are combined to form X′0X′0X′, where X′ can take values ​​from 0 to 3. However, to satisfy the k parameter constraint, which requires that the number of consecutive "0s" cannot exceed 7, X′ in X′0X′0X′ cannot be 0 simultaneously, facilitating subsequent codec design. State 4 lacks a 00300 path, and states 5 and 6 lack a 00003 path, so states 4, 5, and 6 are also discarded. The paths from states 1-3 to 0-3 are identical. The path 00000 is unsuitable for encoding and, after discarding it, states 1-3 can be merged. This merging results in 96 paths, corresponding to the channel code elements 0000X, 00X0X, 0X00X, X000X, X0X0X, 000X0, 0X0X0, X00X0, 00X00, X0X00, 0X000, X0000, where X ranges from 1 to 3. By selecting 64 of these 96 channel code elements and establishing a one-to-one correspondence with the 64 types of source data, the codec table can be constructed and applied to actual optical storage systems to complete data encoding and decoding.

[0071] The fourth-order RLL (1,7) code designed by the present invention has a minimum run and a maximum run of 1 and 7 respectively, and a corresponding theoretical value of the density coefficient is 2.40, and a theoretical value of the capacity is 1.202. The present invention takes into account both the density coefficient and the capacity, and effectively improves the capacity of the optical storage system without changing the optical parameters of the optical storage system. At the same time, the present invention encodes 6-bit source data into 5-bit channel code elements, and its coding efficiency is 6 / 5. The number of corresponding relationships to be established is 64, and the coding efficiency is high while the coding complexity is not high. Therefore, the present invention can take into account the density coefficient, capacity, coding efficiency and coding complexity under the limitations of the multi-order properties of the material and the modulation method, and can be actually applied to the optical storage system to achieve the effect of improving the capacity of the optical storage system.

[0072] In order to further reduce the coding complexity, the present invention further optimizes the coding scheme, as follows:

[0073] Based on the above analysis, the path from state 0 to state 0 is reduced to A, and the path from state 0 to states 1-3 is reduced to B. The path from states 1-3 to 0 is reduced to C, the path to 1 is D, the path to 2 is E, and the path to 3 is F. After the above reduction, the 5-step state transition diagram of the simplified 4th-order RLL (1, 7) code can be drawn, as shown in the figure. Figure 2 shown.

[0074] Through the above steps, the paths in states 1, 2, and 3 are merged into X′0X′0X′ (X′ can be 0-3, but cannot be 0 at the same time), and then 03030, 00030, and 03000 are merged into the 0X0X0 state.

[0075] Through the above merging operation, the channel codewords have several specific formats. In order to minimize the format types of channel codewords while meeting the requirement on the number of channel codewords, the present invention further selects channel codewords with the formats of 00X00, 0X0Y0, and X0Y0Y, totaling 63 types, where X is 1 to 3 and Y is 0 to 3; at the same time, one of the channel codewords with the format of 00X0X is selected.

[0076] Since the formats of these channel codewords have obvious characteristics, in practical applications, for each channel codeword, only three codeword symbols need to be stored at most, and the channel codeword can be determined in combination with a specific format, further reducing the coding complexity.

[0077] In order to further reduce the complexity of encoding and decoding and improve the efficiency of encoding and decoding, the present invention formulates the following carry rules for the selected channel code elements:

[0078] When 00X00 carries, it carries to 0X0Y0;

[0079] When 0X0Y0 carries, carry to X0Y0Y.

[0080] Based on the above carry rule, the present invention further formulates the corresponding relationship between source data and channel code elements as follows: 000001 to 000011 are encoded using channel code elements of the format 00X00. Specifically, 000001 to 000011 correspond to 00100 to 00300 in sequence;

[0081] 000100 to 001111 are encoded using channel symbols of the format 0X0Y0. Specifically, 000100 to 001111 correspond to 01000 to 03030 in sequence.

[0082] 010000 to 111111 are encoded using channel symbols in the format of X0Y0Y. Specifically, 010000 to 111111 correspond to 10000 to 30303 in sequence.

[0083] 000000 corresponds to one of 00X0X; optionally, in the following embodiments, 000000 specifically corresponds to 00303.

[0084] Table 3 Correspondence between source data and channel code elements

[0085] Source data Channel Symbol Source data Channel Symbol 000000 00303 100000 20000 000001 00100 100001 20001 000010 00200 100010 20002 000011 00300 100011 20003 000100 01000 100100 20100 000101 01010 100101 20101 000110 01020 100110 20102 000111 01030 100111 20103 001000 02000 101000 20200 001001 02010 101001 20201 001010 02020 101010 20202 001011 02030 101011 20203 001100 03000 101100 20300 001101 03010 101101 20301 001110 03020 101110 20302 001111 03030 101111 20303 010000 10000 110000 30000 010001 10001 110001 30001 010010 10002 110010 30002 010011 10003 110011 30003 010100 10100 110100 30100 010101 10101 110101 30101 010110 10102 110110 30102 010111 10103 110111 30103 011000 10200 111000 30200 011001 10201 111001 30201 011010 10202 111010 30202 011011 10203 111011 30203 011100 10300 111100 30300 011101 10301 111101 30301 011110 10302 111110 30302 011111 10303 111111 30303

[0086] The above correspondence is specifically shown in Table 3. Based on the correspondence shown in Table 3, a codec table can be established for data encoding and decoding in the optical storage system.

[0087] It should be noted that the correspondence between source data and channel code elements shown in Table 3 above is only a preferred embodiment of the present invention and should not be understood as the sole limitation of the present invention. 64 types of channel code elements are selected from 96 optional types and a one-to-one correspondence is established between them and the 64 types of source data, which can all be used in the present invention.

[0088] The following are examples.

[0089] Example 1:

[0090] A coding and decoding method for a fourth-order RLL (1,7) modulation code, such as Figure 3 As shown, it includes: an encoding step and a decoding step;

[0091] The encoding step includes: dividing the user data into 6-bit source data, converting each source data into a 5-bit channel symbol according to a pre-established codec table, concatenating the channel symbols in sequence, and inserting a merging bit between two adjacent channel symbols to obtain an RLL sequence;

[0092] The decoding step includes: removing one merging bit every five bits of the RLL sequence to be decoded to obtain a 5-bit channel symbol, converting each channel symbol into a 6-bit source data according to the codec table, and sequentially splicing the source data to obtain user data;

[0093] The merging bit is used to ensure that there is at least one "0" between any two non-zero elements in the RLL sequence. Considering that after channel codewords are spliced, two non-zero elements may be directly adjacent. For example, if the channel codewords 00X0X and X0X00 are adjacent, the resulting sequence contains 00X0XX0X00. In this case, the constraint of the minimum run of 1 in the fourth-order RLL (1,7) code is not satisfied. In this embodiment, the merging bit is inserted into adjacent channel codewords. When the adjacent elements before and after the merging bit are non-zero, the value of the merging bit is "0" to prevent non-zero elements from being directly adjacent. In other cases, the value of the merging bit can be any quaternary number, and can also be used to store an error correction flag or to equalize the DC component of the overall signal.

[0094] In this embodiment, the codec table is consistent with the above Table 3. It should be noted that when the correspondence between source data and channel symbols changes, a codec table can be established accordingly.

[0095] Example 2:

[0096] An optical storage controller, comprising:

[0097] a computer-readable storage medium for storing a computer program;

[0098] and a processor, configured to read a computer program stored in a computer-readable storage medium and execute the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided in the first embodiment.

[0099] Example 3:

[0100] A reading and writing method for an optical storage system, such as Figure 4 As shown, it includes: writing operation and reading operation;

[0101] The writing operation includes:

[0102] Encode the user data into an RLL sequence using the encoding step of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided in the first embodiment above;

[0103] Perform NZR modulation on the RLL sequence obtained by encoding to obtain the NZR sequence to be written;

[0104] Writing the NZR sequence to be written into the optical storage medium of the optical storage system;

[0105] The read operation includes:

[0106] Read target data from the optical storage medium to obtain an NZR sequence;

[0107] Performing NZR inverse modulation on the NZR sequence read from the optical storage medium to obtain an RLL sequence;

[0108] The decoding step of the encoding and decoding method using the fourth-order RLL (1,7) modulation code provided in the first embodiment demodulates the RLL sequence obtained by inverse modulation to obtain user data.

[0109] The RLL sequence obtained by encoding the encoding and decoding method provided in the above embodiment 1 cannot be directly written into the optical storage medium and needs to be modulated into the corresponding write waveform. Since the run length limited encoding used in this embodiment is fourth order, the modulation method for the RLL sequence in this embodiment is NZR modulation. Figure 5 The figure shows an example of NZR modulation, and NZR inverse modulation is the inverse process of NZR modulation.

[0110] Example 4:

[0111] A read / write device of an optical storage system, comprising: a write module and a read module;

[0112] The writing module includes:

[0113] an encoding unit, configured to encode user data into an RLL sequence using the encoding steps of the encoding and decoding method of the fourth-order RLL (1,7) modulation code provided in the first embodiment;

[0114] A modulation unit, configured to perform NZR modulation on the RLL sequence obtained by encoding to obtain an NZR sequence to be written;

[0115] and a writing unit for writing the NZR sequence to be written into the optical storage medium of the optical storage system;

[0116] Read modules include:

[0117] A reading unit, used for reading target data from an optical storage medium to obtain an NZR sequence;

[0118] an inverse modulation unit, configured to perform NZR inverse modulation on the NZR sequence read from the optical storage medium to obtain an RLL sequence;

[0119] 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 fourth-order RLL (1,7) modulation code provided in the first embodiment to obtain user data.

[0120] Example 5:

[0121] An optical storage system includes: an optical storage medium, and the reading and writing device of the optical storage system provided in the fourth embodiment.

[0122] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A coding and decoding method for a fourth-order RLL (1,7) modulation code, characterized in that: include: Encoding step and decoding step; The encoding step includes: dividing the user data into 6-bit source data, converting each source data into a 5-bit channel symbol according to a pre-established encoding and decoding table, splicing the channel symbols in sequence, and inserting a merging bit between two adjacent channel symbols to obtain an RLL sequence; The decoding step includes: removing one merging bit every five bits of the RLL sequence to be decoded to obtain a channel codeword with a length of five bits, converting each channel codeword into source data with a length of six bits according to the encoding and decoding table, and sequentially splicing the source data to obtain user data; The merging bit is used to ensure that there is at least one "0" between any two non-zero elements in the RLL sequence; the encoding and decoding table is used to record a one-to-one correspondence between 64 types of 6-bit source data and 64 types of 5-bit channel code elements, where the 64 types of 5-bit channel code elements are 64 of 0000X, 00X0X, 0X00X, X000X, X0X0X, 000X0, 0X0X0, X00X0, 00X00, X0X00, 0X000, and X0000; and the value of X is 1 to 3.

2. The encoding and decoding method of the fourth-order RLL (1,7) modulation code according to claim 1, characterized in that: The 64 5-bit channel symbols include: 00X00, 0X0Y0, X0Y0Y, a total of 63; and 1 of 00X0X; The value of Y ranges from 0 to 4.

3. The encoding and decoding method of the fourth-order RLL (1,7) modulation code according to claim 2, characterized in that: In the encoding and decoding table, the one-to-one correspondence between the 6-bit source data and the 5-bit signal code element is as follows: 000000 corresponds to one of 00X0X; 000001 to 000011 correspond to 00100 to 00300 respectively; 000100 to 001111 corresponds to 01000 to 03030; 010000~111111 corresponds to 10000~30303 respectively.

4. 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 fourth-order RLL (1,7) modulation code according to any one of claims 1 to 3.

5. 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 fourth-order RLL (1,7) modulation code according to any one of claims 1 to 3; Perform NZR modulation on the RLL sequence obtained by encoding to obtain the NZR sequence to be written; Writing the NZR 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 NZR sequence; performing NZR inverse modulation on the NZR sequence read from the optical storage medium to obtain an RLL sequence; The decoding step of the encoding and decoding method of the fourth-order RLL (1,7) modulation code according to any one of claims 1 to 3 demodulates the RLL sequence obtained by inverse modulation to obtain user data.

6. 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 fourth-order RLL (1,7) modulation code according to any one of claims 1 to 3; A modulation unit, configured to perform NZR modulation on the RLL sequence obtained by encoding to obtain an NZR sequence to be written; and a writing unit, configured to write the NZR 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 NZR sequence; an inverse modulation unit, configured to perform NZR inverse modulation on the NZR 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 fourth-order RLL (1,7) modulation code according to any one of claims 1 to 3 to obtain user data.

7. 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 6.

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