Method and device for adaptively controlling code rate for staircase code in wireless communication system

Abstract

The present disclosure relates to a method and a device for adaptively controlling a code rate for a staircase code in a wireless communication system. A method for encoding a staircase code according to an embodiment of the present disclosure, the method being performed by a transmission device in a wireless communication system, comprises the processes of: adjusting a code rate of at least one layer, among all layers of the staircase code, to be relatively lower than code rates of the remaining layers excluding the at least one layer, and adjusting the code rates of the remaining layers to constantly maintain the overall code rate of the staircase code; alternately performing row-wise encoding or column-wise encoding using an element code according to a code rate adjusted for each layer of the staircase code; and transmitting, to a reception device, a staircase code word generated by performing the row-wise encoding or the column-wise encoding.

Description

Method and device for adaptive code rate control for step codes in wireless communication systems

[0001] The present disclosure relates to a communication method and device using a staircase code in a wireless communication system.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of 5G (5th-generation) communication systems, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are expected to evolve into diverse form factors, including augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G."

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes per second (i.e., 1,000 gigabits per second) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster, while the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), beamforming, and multiple antenna transmission technologies such as massive multiple-input and multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive extended reality (Truly Immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through enhanced security and reliability, will find application in diverse fields such as industry, healthcare, automotive, and home appliances.

[0007] Staircase codes are being studied as one of the encoding methods that can be used in next-generation communication systems, such as the aforementioned 5G and 6G communication systems. Staircase codes were first proposed in the field of optical communications in 2012, and at the time, they were introduced as codes that could guarantee excellent performance at very high code rates, using the Bose-Chaudhuri-Hocquenghem (BCH) code as a component code. Staircase codes are known to have very excellent performance, with a difference of only 0.56 dB from the theoretical performance limit of a bit error rate (BER) of 10-15, especially when based on hard decision decoding (HDD).

[0008] The present disclosure provides a method and apparatus for adaptively controlling a code rate for a step code in a wireless communication system.

[0009] The present disclosure provides an encoding / decoding method and device including a code rate control method for a step code in a wireless communication system.

[0010] According to an embodiment of the present disclosure, a method for encoding a staircase code performed in a transmitting device in a wireless communication system includes a process of adjusting a code rate of at least one layer among all layers of the staircase code to be relatively lower than that of the remaining layers excluding the at least one layer, and adjusting the code rates of the remaining layers to maintain the overall code rate of the staircase code constant, a process of alternately performing row-by-row encoding or column-by-column encoding using element codes according to the adjusted code rate in each layer of the staircase code, and a process of transmitting a staircase code code word generated by performing the row-by-row encoding or the column-by-column encoding to a receiving device.

[0011] In addition, according to an embodiment of the present disclosure, a transmitting device for performing encoding of a staircase code in a wireless communication system includes a transceiver, and a processor configured to adjust a code rate of at least one layer among all layers of the staircase code to be relatively lower than that of the remaining layers excluding the at least one layer, adjust the code rates of the remaining layers to maintain the overall code rate of the staircase code constant, alternately perform row-by-row encoding or column-by-column encoding using element codes according to the adjusted code rate in each layer of the staircase code, and transmit a staircase code code word generated by performing the row-by-row encoding or the column-by-column encoding to a receiving device through the transceiver.

[0012] In addition, according to an embodiment of the present disclosure, a method for decoding a staircase code performed in a receiving device in a wireless communication system includes the steps of: receiving, from a transmitting device, a staircase code word whose code rate is adjusted to be relatively lower in at least one layer among all layers of the staircase code than in the remaining layers excluding the at least one layer; and performing row-by-row decoding or column-by-column decoding using an element code according to the adjusted code rate in each layer of the staircase code on the received staircase code word to restore information bits.

[0013] In addition, according to an embodiment of the present disclosure, a receiving device for performing decoding of a staircase code in a wireless communication system includes a transceiver, and a processor configured to receive, from a transmitting device through the transceiver, a staircase code word whose code rate is adjusted to be relatively lower in at least one layer among all layers of the staircase code than in the remaining layers excluding the at least one layer, and to perform row-by-row decoding or column-by-column decoding using an element code according to the adjusted code rate in each layer of the staircase code on the received staircase code word to restore information bits.

[0014] Figure 1a is a diagram showing an example of a configuration of a square matrix-based staircase code.

[0015] Fig. 1b is a diagram for explaining an encoding method using a square matrix-based staircase code of Fig. 1a.

[0016] Figure 2a is a diagram showing an example of a configuration of a non-square matrix-based staircase code.

[0017] Figures 2b and 3 are drawings for explaining an encoding method using a non-square matrix-based staircase code of Figure 2a.

[0018] Figure 4 is a diagram for explaining a decoding method using a square matrix-based staircase code.

[0019] Figure 5 is a diagram for explaining a decoding method using a non-square matrix-based staircase code.

[0020] FIG. 6 is a drawing for explaining a method for controlling the code rate of a step code according to an embodiment of the present disclosure;

[0021] FIG. 7 is a diagram illustrating a method for controlling a code rate by adjusting the length of information bits and the length of parity bits in each layer of a staircase code according to an embodiment of the present disclosure.

[0022] FIG. 8 is a diagram illustrating a code rate control method for omitting an initial matrix of a step code according to an embodiment of the present disclosure;

[0023] FIG. 9 and FIG. 10 are drawings for explaining code rate control methods according to an embodiment of the present disclosure.

[0024] FIG. 11 and FIG. 12 are diagrams showing an example of a code rate control method when an LDPC code is used as an element code in a step code in an embodiment of the present disclosure.

[0025] FIG. 13a is a diagram illustrating an encoding method including code rate control in a step code performed in a transmitting device of a wireless communication system according to an embodiment of the present disclosure;

[0026] FIG. 13b is a diagram illustrating a decoding method including code rate control in a step code performed in a receiving device of a wireless communication system according to an embodiment of the present disclosure; and

[0027] FIG. 14 is a diagram showing an example configuration of a communication device in a wireless communication system according to an embodiment of the present disclosure.

[0028] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0029] For the same reason, some components in the attached drawings are omitted or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0030] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. The various embodiments are provided to ensure that the present disclosure is complete and to fully convey the scope of the present disclosure to those skilled in the art, and the present disclosure is defined solely by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0031] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0032] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0033] The term "~unit" used in various embodiments of the present disclosure refers to a software or hardware component, and the "~unit" performs certain roles. However, the "~unit" is not limited to software or hardware. The "~unit" may be configured to reside on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the "~unit" includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and "~units" may be combined into a smaller number of components and "~units" or further separated into additional components and "~units." In addition, the components and "~units" may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in various embodiments of the present disclosure, '~bu' may include one or more processors.

[0034] In this disclosure, phrases such as “A and / or B”, “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B, or C”, “at least one of A, B, and C”, and “at least one of A, B, or C” can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as “first”, “second”, or “first” or “second” may be used simply to distinguish the corresponding component from other corresponding components and do not limit the corresponding components in any other respect (e.g., importance or order).

[0035] In embodiments of the present disclosure, a user equipment (UE) may be a terminal, a mobile station (MS), a cellular phone, a smartphone, a computer, or any other electronic device capable of performing a communication function. In addition, a base station (BS) is a network entity that performs resource allocation to a UE, and may be at least one of a Node B, an eNB (eNode B), a gNB (gNode B), a wireless access unit, a base station controller, or a node on a network.

[0036] Furthermore, the various embodiments of the present disclosure described below may be applied to other communication systems having similar technical backgrounds or channel configurations. Furthermore, the various embodiments of the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0037] In specifically describing various embodiments of the present disclosure, the communication system may utilize a wireless communication system, and for example, may utilize a 5G communication system based on the 5G communication standard (NR (New RAN)) proposed by 3GPP (3rd generation partnership project long term evolution), a wireless communication standard standardization organization. In addition, it may be applied to other communication systems with similar technical backgrounds with slight modifications within a range that does not significantly deviate from the scope of the present disclosure, and this may be possible at the discretion of a person skilled in the technical field of the present disclosure. For the convenience of the following description, some terms and names defined in the 3GPP standard may be used. However, the present disclosure is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

[0038] To facilitate understanding of the embodiments of the present disclosure, a staircase code will first be described. The staircase code can be viewed as a type of product code that has the characteristics of both a block code and a convolutional code. This can be easily understood through the structure of the staircase code. In the staircase code, a single level of stairs is formed by sequentially stacking M codewords of the same length encoded with a preset element code (e.g., a low density parity check (LDPC) code, a linear code including a polar code, etc.) as a row / column vector to create a matrix.

[0039] And if the rightmost M columns / rows of the codewords that make up the staircase code are regarded as rows / columns, and new information bits are added to each row and encoding is performed with the element code in the same way, a layer composed of new M codewords can be formed. Afterwards, when forming the next layer of the staircase code, the same operation is repeated in reverse, and if this process is repeated k times, the number of layers, a staircase code with k layers can be generated.

[0040] Here, double encoding is performed on the M overlapping rows (or columns) of each adjacent layer of the staircase code, and through individual decoding at each layer, the hard decision estimate value in the case of hard decision decoding, or the log likelihood ratio (LLR) value in the case of soft decision decoding (SDD), is transferred to the overlapping part of the adjacent layer, so there is a decoding error rate performance gain through this. In addition, the staircase code is a code that has the advantage of being able to completely parallelize the decoding of codewords corresponding to each row of a specific layer, and can also parallelize the decoding of non-adjacent layers as needed, so that the tradeoff between the error rate performance and the decoding delay can be adjusted during decoding.

[0041] Hereinafter, with reference to FIGS. 1A to 4, a method for encoding / decoding a staircase code based on a square matrix or a non-square matrix will be described. [Table 1] below defines the parameters referenced in the description of the staircase code.

[0042] [Table 1]

[0043]

[0044] First, the above-described staircase code can be expressed by dividing it into two forms: a staircase code based on a square matrix and a staircase code based on a non-square matrix (or fat matrix). In the following disclosure, the square matrix constituting the staircase code when encoding in a transmitting device is denoted as “A”, and the non-square matrix is ​​denoted as “B”. In addition, the square matrix constituting the staircase code when decoding in a receiving device is denoted as “X”, and the non-square matrix is ​​denoted as “Y”. In the following embodiments, in the square matrix-based staircase code, the first layer includes an initial matrix and one square matrix, and each layer of the remaining layers includes an overlapping portion with the previous layer (e.g., a square matrix) and one square matrix. In a non-square matrix-based staircase code, the first layer includes an initial matrix and one non-square matrix, and the remaining layers include an overlapping portion with the previous layer (e.g., a square matrix) and one non-square matrix. If the overlapping portion is regarded as one matrix, each layer in a square matrix or non-square matrix-based staircase code can be understood as including two matrices. In addition, the number of matrices included in each layer of the remaining layers in a square matrix or non-square matrix-based staircase code can be one or more. If the number of matrices included in each layer is one, the matrix can be understood as including the overlapping portion.

[0045] Figure 1a is a diagram showing an example of a configuration of a square matrix-based staircase code.

[0046] Referring to Fig. 1a, a square matrix is ​​a matrix in which the number of rows and the number of columns are the same, and Fig. 1a illustrates a staircase code based on a square matrix with a number of layers (k) of 5. Referring to Fig. 1a, a staircase code composed of, for example, 6 square matrices (A0, A1, A2, A3, A4, A5) having a size of M×M is illustrated, but if the number of matrices is 3 or more, a staircase code including overlapping portions can be formed. The number of layers, 5, is merely an example and may be 2 or more. In the example of Fig. 1a, two square matrices (A0, A1) form a first layer (110) in the staircase code, two square matrices (A1, A2) form a second layer (120), and in the same manner, a staircase code having multiple layers (or tiers) of a third layer, a fourth layer, and a fifth layer can be formed. And the first layer and the second layer have overlapping parts of A1, and the second layer and the third layer have overlapping parts of A2. In the same way, other layers may also have overlapping parts. In the staircase code, the decoding reliability can be improved through the overlapping parts. In the staircase code, the first matrix (or initial matrix) (A0) can be filled with, for example, all elements of the matrix with values ​​of 0 (or predetermined values) and can indicate the starting point of the staircase code. Since the staircase code based on a square matrix such as Fig. 1a has low complexity in encoding / decoding, a transmitting device and a receiving device using the staircase code can be implemented with low complexity.

[0047] Fig. 1b is a diagram for explaining an encoding method using a square matrix-based staircase code of Fig. 1a.

[0048] In the example of FIG. 1b, the first layer (110) of the staircase code includes a matrix (A0) (111) of size M×M and a matrix (A1) of size M×M. All elements of the matrix (A0) have, for example, a value of 0 (or a predetermined value), and the matrix (A1) includes an information portion (112) and a parity portion (113). The information portion (122) is filled with new information bits. For example, the parity portion (113) may be filled through row-wise encoding for each of the five rows of the first layer (110). That is, encoding is performed row-by-row using element code C, such as LDPC code, polar code, BCH code, etc., for the information bits of each row of the matrix (A0) and matrix (A1) of the first layer (110), to generate parity bits, and the parity bits are filled in the corresponding row of the parity part (113).

[0049] In the example of FIG. 1b, the second layer (120) of the staircase code includes a matrix (A1) (121) of size M×M and a matrix (A2) of size M×M. The second layer (120) includes the matrix (A1) and the matrix (A2), and the matrix (A1) corresponds to an overlapping portion of the first layer (110) and the second layer (120). The matrix (A2) of the second layer (120) includes an information portion (122) and a parity portion (123). The information portion (122) is filled with new information bits. For example, the parity portion (123) may be filled through column-wise encoding for each of the five columns of the second layer (120). Encoding using element code C, such as LDPC code, polar code, BCH code, etc., is performed column-by-column on the information bits of each column of the matrix (A1) and matrix (A2) of the second layer (120) to generate parity bits, and the parity bits are filled in the corresponding column of the parity part (123).

[0050] As described above, the encoding method using a square matrix-based staircase code is performed by alternating row-wise encoding or column-wise encoding in units of layers consisting of two square matrices, for example, and one square matrix is ​​overlapped between adjacent layers. In the case of the square matrix-based staircase code, the code length N of the element codeword in each layer consisting of two matrices C is simplified to twice M, and the number of information bits K Ccan be simply calculated as (2M-r). r is the number of parity bits of the element codeword. As a generalized example, in the above square matrix-based staircase code, the two matrices constituting each layer can be referred to as the first matrix and the second matrix, and when n is 2 or greater, the first matrix in the n-th layer overlaps the second matrix in the n-1th layer, and the first matrix in the n+1th layer overlaps the second matrix in the n-th layer.

[0051] Figure 2a is a diagram showing an example of a configuration of a non-square matrix-based staircase code.

[0052] Referring to Fig. 2a, a non-square matrix is ​​a matrix in which the number of rows and the number of columns are different, and Fig. 2a illustrates a staircase code based on a non-square matrix with a layer number (k) of 5. Referring to Fig. 2a, for example, a staircase code is illustrated consisting of a first matrix (initial matrix) (B0) of size M×M and a plurality of non-square matrices (B1, B2, B3, B4, B5) of size M×(NM) or (NM)×M. However, if the number of matrices constituting the staircase code is 3 or more, a staircase code including an overlapping portion between adjacent layers can be formed. In Fig. 2a, a first layer (210) of the staircase code includes a matrix (B0) and a matrix (B1), a second layer (220) includes at least a portion (201) of the matrix (B1) and a matrix (B2), and a third layer includes at least a portion of the matrix (B2) and a matrix (B3). Also, the second layer (220) may include at least a portion (201) of the matrix (B1) and the matrix (B2), and the third layer may include at least a portion (202) of the matrix (B2) and the matrix (B3). In the same manner, a staircase code having multiple layers (or tiers) of the fourth layer and the fifth layer may be formed. In Fig. 2a, the first layer (210) and the second layer (220) have overlapping portions (201) corresponding to at least a portion of the matrix (B1), and the second layer (220) and the third layer have overlapping portions (202) corresponding to at least a portion of the matrix (B2). In the same manner, other layers may also have overlapping portions. In the staircase code, the decoding reliability can be improved through the overlapping portion(s).

[0053] In Fig. 2a, the overlapping portion assumes an example having a size of M×M. In the staircase code, the first matrix (initial matrix) (B0) may be filled with, for example, all elements of the matrix having values ​​of 0 (or predetermined values), and may indicate the starting point of the staircase code. Since the staircase code based on a non-square matrix as in Fig. 2a has low complexity in encoding / decoding, a transmitting device and a receiving device using the staircase code can be implemented with low complexity. As a generalized example, the two matrices constituting each layer in the staircase code based on a non-square matrix may be referred to as a first matrix and a second matrix, and the second matrix uses a non-square matrix. When n is 2 or more, the first matrix in the n-th layer overlaps at least a portion of the second matrix in the n-1th layer, and the first matrix in the n+1th layer overlaps at least a portion of the second matrix in the nth layer. And, the first matrix (initial matrix) of the staircase code and the first matrix corresponding to the overlapping portion when n is 2 or greater can use square matrices. As an optional embodiment, it is also possible to configure at least one of the first matrix (initial matrix) and the first matrix corresponding to the overlapping portion as a non-square matrix.

[0054] FIG. 2b and FIG. 3 are drawings for explaining an encoding method using a non-square matrix-based staircase code of FIG. 2a.

[0055] In Fig. 2b, the first layer (210) of the staircase code includes a matrix (B0) (211) of size M×M and a matrix (B1) of size M×(NM). All elements of the matrix (B0) have, for example, a value of 0, and the matrix (B1) includes an information portion (212a or 212b) and a parity portion (213a or 213b). Fig. 2b (a) illustrates a case where the size of the parity portion (213a) is larger than that of the information portion (212a), and Fig. 2b (b) illustrates a case where the size of the information portion (212b) is larger than that of the parity portion (213b). The information portion (212a or 212b) is filled with new information bits. For example, in the first layer (210), the parity portion (213a or 213b) can be filled in through row-wise encoding for each of the five rows. Reference numeral 21 indicated by a dotted line in FIG. 2b illustrates a boundary line of the overlapping portion of the first layer (210) and the second layer (220). In the matrix (B0) and the matrix (B1), encoding using an element code C, such as an LDPC code, a polar code, or a BCH code, is performed row-by-row for the information bits of each row to generate parity bits, and the parity bits are filled in the corresponding row of the parity portion (213a or 213b). In addition, as in the example of FIG. 2b, in the overlapping portion between adjacent layers in the staircase code, a case where information bits and parity bits are mixed (FIG. 2b (b)) and a case where only parity bits exist (FIG. 2b (a)) can be considered.

[0056] For convenience of explanation, the example of Fig. 3 shows an encoding method performed in the second layer (220) of a staircase code, assuming that the size of the parity portion (213a) is larger than the information portion (212a), as in the example of (a) of Fig. 2b. The method of Fig. 3 can be equally applied to the example of (b) of Fig. 2b. Referring to Fig. 3, the second layer (220) of the staircase code includes at least a portion (201) of a matrix (B1) and a matrix (B2) having a size of (NM)×M. At least a portion (201) corresponding to the overlapping portion of the first layer (210) and the second layer (220) in the staircase code is a matrix having a size of M×M, and the matrix (B2) includes an information portion (222) and a parity portion (223). The information portion (222) is filled with new information bits. For example, in the second layer (220), the parity part (223) can be filled in through column-wise encoding for each of the five columns. Encoding is performed column-by-column using an element code C, such as an LDPC code, a polar code, or a BCH code, for the information bits of each column of the overlapping part (201) and the matrix (B2), to generate parity bits, and the parity bits are filled in the corresponding column of the parity part (223). The overlapping part (201) can be virtually rotated by, for example, 90 degrees when encoding together with the matrix (B2). As described above, the encoding method using a staircase code based on a non-square matrix is ​​performed by alternating row-wise encoding or column-wise encoding, and at least a portion of the non-square matrix is ​​provided as an overlapping part between adjacent layers.

[0057] In the present disclosure, for the non-square matrix-based step code, only the relationship between M and r in [Table 1] is sufficient for N C Wow K CSince it is not possible to express the number of information bits of the element codeword and the code length of the element codeword, the number of information bits of the element codeword and the code length of the element codeword are displayed separately. And in the case of the step code based on the square matrix, N C Wow K C may not be indicated separately.

[0058] In the example of Fig. 3, the encoding method using a non-square matrix-based staircase code is specifically explained. First, the elements of the initial matrix (B0) of size M×M can be filled with 0, meaning that no information is loaded, or information bits can be filled. In the case of a square matrix-based staircase code, the matrix is ​​filled in all layers. Although it is composed of square matrices of size M×M, in the case of a non-square matrix-based staircase code, the initial matrix (B0) of the first layer is composed of a square matrix of size M×M, and the remaining matrices in each layer of the staircase code are can be composed of non-square matrices of size M×(NM) or (NM)×M.

[0059] Step 1: Matrix B that constructs the step code i First, to form (i=1, 2, …, k) B i A total of M(NMr) information bits can be inserted into the left (NMr) columns by row or column, or in any method or order, where r is the number of parity bits. The example in Fig. 3 is a matrix B i It is assumed that row-by-row encoding is performed in matrix B, although not shown in Fig. 3. i Column-wise encoding can be performed in which case the encoding operations in steps 2 and 3 below are performed on the matrix B in step 1 above. i The opposite operation can be performed when row-by-row encoding is performed.

[0060] Step 2: Then, for each row, the matrix B of the previous layer i-1By treating the M bits corresponding to the overlapping portion (201) as information bits and performing encoding using the element code C on the total (Nr) information bits including the newly inserted (31) information bits (222), r parity bits (223) can be generated in units of columns or rows. By applying the corresponding operation equally to all rows, a new staircase (or matrix) can be generated.

[0061] Step 3: From the second layer onwards, the operations can be divided into two according to the stair index i. For example, if i is even, the matrix B of the previous layer i-1 The rightmost M columns can be virtually rotated 90° counterclockwise. That is, the overlapping portion can be formed by rows with the rightmost column at the top. Based on the matrix composed of M rows thus created, the matrix B is located on the right. i The operations of steps 1 and 2 above can be performed to generate a new layer matrix B generated in this way. i The matrix B of the previous layer of the existing structure before performing the virtual rotation i-1 It is pasted at the bottom of the rightmost M columns. In addition, if the index i of the layer is even, since the previous layer is a layer that performed row-by-row encoding, the first row of the next layer can be configured from the rightmost M columns of the previous layer for encoding in the next layer, and the total M columns of the previous layer can be rotated in order to become the M rows of the next layer.

[0062] If the layer index i above is odd, the matrix B of the previous layer i-1 Matrix B on the right side of the bottom M rows based on iThe operations of steps 1 and 2 above can be performed to generate . When the layer index is i, row-by-row encoding can be performed on the lowermost M rows of the previous layer (i-1), in which case operations such as 90-degree rotation are not required.

[0063] Step 4: If the operations of steps 1 to 3 described above are repeated a total of k times, a staircase code consisting of k layers can be generated.

[0064] The encoding method using the overlapping portion and virtual rotation in steps 1 to 4 above can be applied in the same manner to a square matrix-based staircase code.

[0065] In the case where no information is loaded in the initial matrix B0 of the first layer from the codeword of the staircase code generated in the above manner, the codeword obtained by reading all bits of the matrix B1 excluding the initial matrix B0 in the first layer and the matrices (B2, B3, …) in the remaining layers as row or column vectors regardless of the order can be defined as the final codeword. As an optional embodiment, in the case where the initial matrix B1 in the first layer contains information bits, all matrices (B0, The codeword obtained by reading all bits of B1B2, B3, … as a row or column vector regardless of the order can be defined as the final codeword. This definition can be applied to both square matrix-based step codes and non-square matrix-based step codes.

[0066] In the following description of the present disclosure, for convenience, it is assumed that the initial matrix B0 does not contain information bits and is filled with, for example, values ​​of 0.

[0067] [Table 2] below shows the code rate (R) of the element codeword in the non-square matrix-based step code mentioned above. C ) and the total code rate (R) of the staircase code tot) is an example.

[0068] [Table 2]

[0069]

[0070] For non-square matrix-based staircase codes, the total code length N of the codewords tot can be calculated as kM(NM), and for square matrix-based step codes, it is in simpler form kM 2 can be expressed as kM(Nr) for non-square matrix-based step codes or kM(Mr) for square matrix-based step codes. In the case of square matrix-based step codes, the code rate is the code rate of the element codeword. and total code rate Comparing them, it can be seen that the code rate of the element codeword is higher. In other words, if the code rate of the entire codeword of the staircase code is increased, the code rate of the element codeword increases to a larger value, which has a great impact on the performance of the element code. Figure 4 is a diagram for explaining a decoding method using a square matrix-based staircase code.

[0071] The square matrix-based staircase code can be encoded using the encoding method of Fig. 1b as described above, and can be decoded using the decoding method of Fig. 4. Decoding can utilize decoding using the element code C of the LDPC code, polar code, BCH code, etc. used during encoding.

[0072] First, it is assumed that the transmitting device encodes and transmits a staircase code composed of a plurality of square matrices (A0, A1, A2, A3, A4, A5) having a size of M×M using a staircase code based on a square matrix with a layer number (k) of 5, as in the examples of FIGS. 1a and 1b. The receiving device can receive / obtain a staircase code composed of six square matrices (X0, X1, X2, X3, X4, X5) having a size of M×M, as in FIG. 4 (a). At this time, if the initial matrix (A0) has a value of 0 (or a predetermined value), for example, what is actually received by the receiving device is a staircase code of five square matrices (X1, X2, X3, X4, X5), and the receiving device fills the initial matrix (X0) of the staircase code with a value of 0 (or a predetermined value) like the initial matrix (A0). The receiving device can decode information bits by performing row-wise decoding on the matrices (X4, X5) of the fifth layer in step 401, column-wise decoding on the matrices (X3, X4) of the fourth layer in step 402, and alternately performing row-wise decoding or column-wise decoding on the third layer to the first layer in steps 403 to 405 in the same manner as in (b) of FIG. 4. In addition, as an optional example, it is also possible to decode information bits by alternately performing row-wise decoding or column-wise decoding in the reverse order from the first layer to the fifth layer.

[0073] Figure 5 is a diagram for explaining a decoding method using a non-square matrix-based staircase code.

[0074] A non-square matrix-based staircase code can be encoded using the encoding method of Fig. 3 as described above, and can be decoded using the decoding method of Fig. 5. Decoding can utilize decoding using the element code C of the LDPC code, polar code, BCH code, etc. used during encoding.

[0075] First, it is assumed that the transmitting device encodes and transmits a staircase code composed of a first matrix (initial matrix) (B0) of size M×M and five non-square matrices (B1, B2, B3, B4, B5) of size M×(NM) or (NM)×M, as in the examples of FIG. 2a to FIG. 3, based on a non-square matrix with a layer number (k) of 5. The receiving device can receive / acquire a first matrix (initial matrix) (Y0) of size M×M and five non-square matrices (Y1, Y2, Y3, Y4, Y5) of size M×(NM) or (NM)×M, as in (a) of FIG. 5. At this time, if the initial matrix (B0) has, for example, a value of 0 (or a predetermined value), what is actually received by the receiving device is a staircase code of five non-square matrices (Y1, Y2, Y3, Y4, Y5), and the receiving device fills the initial matrix (Y0) of the staircase code with a value of 0 (or a predetermined value) like the initial matrix (B0). As shown in (b) of FIG. 5, the receiving device performs row-wise decoding on the matrices (Y4, Y5) of the fifth layer in step 501, column-wise decoding on the matrices (Y3, Y4) of the fourth layer in step 502, and in the same manner, alternately performs row-wise decoding or column-wise decoding on the third layer to the first layer in steps 503 to 505 to decode the information bits. Additionally, as an optional example, it is also possible to decode information bits by alternately performing row-by-row decoding or column-by-column decoding in reverse order from the first layer to the fifth layer in Fig. 5 (b).

[0076] Due to the structural characteristics of the above-mentioned staircase code, if an incorrect reliability value (e.g., a value with a small absolute value of reliability or a value with an opposite sign to the original value) from an adjacent layer is propagated to other layers through the overlapping part of the staircase code during the decoding process, the error correction capability of the element codeword that performs decoding with the incorrect reliability value in the receiving device is affected, which leads to error propagation that causes a decrease in performance when decoding the codeword of the entire staircase code.

[0077] In the structure of the existing staircase code, a simple method is adopted in which encoding and decoding corresponding to the same code rate are performed for the same information bit lengths for all rows or columns of all layers. In this way, when the same code rate is applied to all layers of the staircase code, the decoding initial layer that does not receive sufficient protection from adjacent layers may have a relatively lower error correction capability than other layers. The decoding initial layer may be, for example, the first layer or the last layer among all layers of the staircase code.

[0078] In this disclosure, a method for adjusting / controlling the code rate for each layer of a staircase code is proposed. That is, the decoding capability of the decoding starting layer can be improved by lowering the code rate of the decoding starting layer (by fixing the number of information bits but increasing the length of the parity bits, or increasing the lengths of the information bits and parity bits together) or by keeping the code rate of the decoding starting layer the same as that of other layers but increasing the code length itself (for example, by increasing the lengths of the information bits and parity bits in the decoding starting layer at the same rate). Through this, the error propagation phenomenon described above in the staircase code can be prevented in advance and the overall error rate performance can be improved. At this time, in order to keep the total resource allocation scheduled in the staircase code the same, the code rates in layers other than the decoding starting layer with the adjusted code rate can be additionally adjusted / controlled to make the number of information bits and the number of code bits the same from the perspective of the entire staircase code. In other words, the overall code rate of the staircase code If the decryption starting point layer is the first layer with layer index i=1, the code rate of the matrix (B1) of the first layer is If the matrix of other layers (i=2, …, k) other than the first layer is increased by that amount (B i ) by appropriately adjusting / controlling at least one code rate among them to obtain the overall code rate R. tot to be able to maintain it.

[0079] FIG. 6 is a diagram for explaining a method for controlling the code rate of a step code according to an embodiment of the present disclosure.

[0080] In the example of Fig. 6, among the parameters of the step sign in [Table 1], the parameters Parameters that are adjusted / controlled at each level of the staircase sign (i is the layer index, i=1, 2, …, k) can be represented as a combination of N c is the code length of the element codeword, Kc is the number of information bits of the element codeword, r is the number of parity bits of the element codeword, and if the code rate control method of the present disclosure is not applied, the above parameters can be set identically across all layers of the staircase code. When the code rate control method of the present disclosure is applied, the parameters can be adjusted / controlled at each level of the staircase code. At the i-th level of the staircase code, N i is the adjusted / controlled code length of the element codeword, K i is the number of adjusted / controlled information bits in the element codeword, r i represents the number of adjusted / controlled parity bits in the element codeword.

[0081] Below [Mathematical Formula 1] are the parameters controlled in the present disclosure. This is an example of defining .

[0082] [Mathematical Formula 1]

[0083]

[0084] Referring to Figure 6, the i-th layer is a matrix (B') having a size of M×M. i-1 ) and M×(N i -M) matrix with size B i ) can be composed of. Here is a matrix (B') with size M×M i-1 ) may be an overlapping portion (601) between the previous layer i-1 and the i layer. Specifically, the M element codewords of the i-th layer each have M information bits and new information bits in the overlapping portion (601) with the previous layer. A total of K in combination with the dog i It contains K information bits, and the transmitting device transmits K bits in each row. i For the information bits (602), encoding is performed row-by-row using element codes C, such as LDPC codes, polar codes, and BCH codes, for example.i The parity bits (603) are generated and the corresponding rows of the parity part are filled with the parity bits (603). A total of N are generated through row-by-row encoding in each layer of the i-th layer. i An element codeword consisting of encoded bits is generated. Therefore, the code rate R of the element codeword in the i-th layer c,i can be calculated / defined as shown in [Mathematical Formula 2] below.

[0085] [Equation 2]

[0086]

[0087] By using the parameters defined as in [Mathematical Formula 1] and [Mathematical Formula 2] above, the number of new information bits, the number of parity bits, and the code rate can be controlled to have different values ​​in each layer of the staircase code. However, in order to maintain consistency in the amount of resource allocation from a system perspective in cases where the code rate control method of the present disclosure is applied and not applied, the condition as in [Mathematical Formula 3] below, that is, the number of new information bits and parity bits r i We can define total sum conditions for . In this disclosure, Wow r i It is possible to perform code rate control for various combinations, and specific examples will be described later.

[0088] [Equation 3]

[0089]

[0090] In the present disclosure, the decoding performance can be improved by adjusting the code rate of the decoding starting layer of the step code to be relatively lower than that of the remaining layers, and adjusting the code rates of the remaining layers to maintain the overall code rate of the step code constant according to the overall sum maintenance condition of the above [Mathematical Formula 3]. In the following embodiments: Wow r iEach represents the number of new information bits and the number of parity bits, and can also represent new information bits and parity bits. In addition, since the encoding of the staircase code is performed by alternating row-by-row encoding and column-by-column encoding, the above-described embodiment of Fig. 6 can be applied in the same manner to the layer(s) where column-by-column encoding is performed.

[0091] FIG. 7 is a diagram illustrating a method for controlling a code rate by adjusting the length of information bits and the length of parity bits in each layer of a staircase code according to an embodiment of the present disclosure.

[0092] Referring to FIG. 7, the first layer (710) of the staircase code includes a matrix (B0) of size M×M and a matrix (B1) of size M×N1. In (a) of FIG. 7, the matrix (B1) includes new information bits and parity bits. The second layer (720) includes a matrix (B'1) of size M×M and a matrix (B2) of size M×N2. The matrix (B2) includes new information bits and parity bits. And the third layer (730) includes a matrix (B'2) of size M×M and a matrix (B3) of size M×N2. The matrix (B3) includes new information bits and parity bits. Reference numbers 701, 702, and 703 correspond to adjacent layers and overlapping portions in the corresponding layers, respectively. The overlapping portion (701) may correspond to the matrix (B'1), and the overlapping portion (702) may correspond to the matrix (B'2). In (b) of Fig. 7, encoding using an element code C, such as an LDPC code, a polar code, or a BCH code, is performed row by row for the information bits of each row of the matrix (B0) and matrix (B1) of the first layer (710), to generate parity bits, and the parity bits are filled in the corresponding row. Encoding using an element code C is performed column by column for each of the columns of the second layer (720), to generate parity bits, and the parity bits are filled in the corresponding row. Encoding using an element code C is performed column by column for each of the columns of the second layer (720), to generate parity bits, and the parity bits are filled in the corresponding row.

[0093] In the example of Fig. 7, if the first layer (710) is the decryption starting layer, a matrix (B1) of size M×N1 is used to store new information bits. and parity bits r i The code rate of the first layer (710) can be adjusted / controlled so that at least one of them is included more than the other layers. And new information bits are generated in the second layer (720) and the third layer (730) according to the overall sum maintenance condition of the above [Mathematical Formula 3]. and parity bits ri By adjusting / controlling, the overall code rate of the staircase code can be kept constant. The example of Fig. 7 shows an example in which the second layer (720) and the third layer (730) are adjusted / controlled to include fewer new information bits and parity bits than the first layer (710).

[0094] In the present disclosure, when the code rate control method is applied, the parameters The criterion for determining the combination may be determined based on where the decoding starting point layer is. The decoding starting point layer may be, for example, the first layer or the last layer among all layers of the staircase code, and may be determined based on whether the decoding order in the receiving device starts from the first layer or the last layer. In an optional embodiment, the decoding starting point layer may be determined based on the type of decoder used in the receiving device. In an optional embodiment, the decoding starting point layer may be indicated to the transmitting device through setting information transmitted to the receiving device, or may be indicated through control information transmitted from the receiving device to the transmitting device.

[0095] Also the above parameters It is possible to determine possible combinations depending on the channel environment. Assuming a situation where it is known empirically or experimentally that errors frequently occur in a specific band or bits corresponding to the band, it is also possible to consider a method of adjusting the code rate of the layer containing the corresponding bit index in the staircase code. In addition, the modulation order: ) according to the parameters We can also consider a combination of these, that is, a method of adjusting the code rate.

[0096] In this disclosure, new information bits are added to each layer of the staircase code for adaptive code rate control of the staircase code. and parity bits r ican be adjusted by one of the methods 1 to 4 below.

[0097] - Method 1: Fixed , fixed r i = r

[0098] - Method 2: Fixed , variable r i

[0099] - Method 3: Variable , fixed r i = r

[0100] - Method 4: Variable , variable r i

[0101] Information indicating a method applied for adaptive code rate control among the above methods 1 to 4 may be provided from a transmitting device (e.g., a base station) to a receiving device (e.g., a terminal) via signaling information (control information). If it is determined that there is no significant change in the applied method depending on the communication system environment and target scenario, the signaling information may be transmitted from the transmitting device to the receiving device using Radio Resource Control (RRC), or if there is a need to change the adaptively applied method, using a combination of at least one of Downlink Control Information (DCI) and MAC-CE (Medium Access Control-Control Element).

[0102] In the present disclosure, a code rate control method can be indicated from a transmitting device to a receiving device through an example such as the following example. For example, the control information (RRC or DCI) (“CodeRateForStairs”) indicating a code rate adjustment method may be configured as a 4-bit sequence, and if the 4-bit sequence is “00XX”, it may indicate method 1, if it is “01XX”, it may indicate method 2, if it is “10XX”, it may indicate method 3, and if it is “11XX”, it may indicate method 4. In the 4-bit sequence, the first two bits may indicate one of the four methods of methods 1 to 4, and the remaining two bits (XX) may support a degree of freedom to indicate detailed options for each method. The above code rate control method using the 4-bit sequence is an example, and if the degree of freedom to indicate detailed options for each method can be selected more specifically according to the channel environment, terminal category, element code used, etc., the control information can be configured with a sequence of 4 bits or more.

[0103] When the code rate control method of the present disclosure is applied, the code rate can be freely adjusted / controlled at each layer of the staircase code. In this case, as an optional embodiment, in order to maintain the form of the staircase code, the first matrix (or initial matrix) (B0) (810) of size M×M, in which all elements of the matrix are filled with 0 values ​​(or predetermined values), can be omitted, as in the example of FIG. 8.

[0104] FIG. 8 is a diagram illustrating a code rate control method for omitting an initial matrix of a staircase code according to an embodiment of the present disclosure.

[0105] Referring to Fig. 8, the first layer (810) of the staircase code includes a matrix (B1) of size M×N1. In (a) of Fig. 8, the matrix (B1) includes new information bits and parity bits. At this time, the first matrix (or initial matrix) (B0) (810) of size M×M may be omitted, unlike the example of Fig. 7. The second layer (820) includes a matrix (B'1) of size M×M and a matrix (B2) of size M×N2. The matrix (B2) includes new information bits and parity bits. And the third layer (830) includes a matrix (B'2) of size M×M and a matrix (B3) of size M×N2. The matrix (B3) includes new information bits and parity bits. Reference numbers 801, 802, and 803 respectively correspond to overlapping portions with adjacent layers in the corresponding layers. The overlapping portion (801) may correspond to the matrix (B'1), and the overlapping portion (802) may correspond to the matrix (B'2). In (b) of Fig. 8, encoding using the element code C is performed row by row on the information bits of the matrix (B0) of the first layer (810) and each row of the matrix (B1), to generate parity bits, and the parity bits are filled in the corresponding row. Encoding using the element code C is performed column by column on each of the columns of the second layer (820), to generate parity bits, and the parity bits are filled in the corresponding row. Encoding using the element code C is performed column by column on each of the columns of the second layer (820), to generate parity bits, and the parity bits are filled in the corresponding row.

[0106] In the example of Fig. 8, if the first layer (810) is the decryption starting layer, a matrix (B1) of size M×N1 is used to store new information bits. and parity bits r i The code rate of the first layer (810) can be adjusted / controlled so that at least one of them is included more than the other layers. And new information bits are generated in the second layer (820) and the third layer (830) according to the overall sum maintenance condition of the above [Mathematical Formula 3]. and parity bits r i By adjusting / controlling, the overall code rate of the step code can be kept constant. The example of Fig. 8 shows an example in which the second layer (820) and the third layer (830) are adjusted / controlled to include fewer new information bits and parity bits than the first layer (810).

[0107] Hereinafter, specific examples of the above methods 1 to 4 will be explained by dividing them into [Example 1] to [Example 4].

[0108] [Example 1: Fixed , fixed r i ]

[0109] Example 1 corresponds to a case where the code rate control method of the present disclosure is not applied to the step code. In this case, new information bits are generated in each layer (910, 920, 930) including the overlapping portions (901, 902, 903), as in the examples of (a) and (b) of FIG. 9. and parity bits r i The number of bits is the same. The total number of information bits to be transmitted from the transmitter, K tot and the overall code rate R tot When the setting information (control information) of [Table 1] is determined, the total code length N tot is determined, and through this, the encoding parameters (number of layers k, number of rows M in each layer) required for the staircase code can be determined from various conditions such as the requirements of the communication system or other environmental factors. At this time, the parameters of the element codeword of each layer can be calculated as shown in [Table 3] below.

[0110] [Table 3]

[0111]

[0112] In method 1, the number of new information bits in the element codeword of each layer is Is is fixed, and the number of parity bits is ri is fixed to the same value of r calculated above. That is, Wow r i are all set to fixed values. Method 1 can be indicated by setting the first two bits of the sequence "CodeRateForStairs", which is control information transmitted by the transmitting device, to "00" as described above. Method 1 can ensure consistency and simplicity of the system. In Method 1, the same encoder and decoder can be used for all codewords of all layers in the staircase code, so simplicity from a design and operation perspective can be guaranteed.

[0113] [Example 2: Fixed , variable r i ]

[0114] Example 2 corresponds to the case where the code rate control method of the present disclosure is applied to a step code. In this case, as in the examples of (a) and (b) of FIG. 10, the number of new information bits in each layer (1010, 920, 930) including the overlapping portion (1001, 1002, 1003) is are the same, and the number of parity bits r i can be changed. As in Example 1, the total number of information bits to be transmitted by the transmitting device K tot and the overall code rate R tot can be determined through the setting information (control information) of the above [Table 1]. And the parameters of the element codeword of each layer can be calculated as in the above [Table 3]. In Method 2, the number of new information bits in the element codeword of each layer Is It can be adjusted as follows. And the number of parity bits r of the element codewords of the layer to which protection is to be applied by adjusting the code rate i can be increased beyond the predetermined value r. At this time, in other layers, new information bits are added according to the overall sum maintenance condition of [Mathematical Formula 3]. and parity bits r i The overall code rate of the staircase code can be kept constant by adjusting / controlling the number of parity bits r in each layer. For example, if the decoding starting layer is the first layer containing the matrix B1, i The way to decide could be as follows:

[0115] - In the first layer containing matrix B1, the number of parity bits is increased by 10% to improve decryption capability. In [Mathematical Formula 4], the parity bit increment is can be calculated by any condition or formula.

[0116] [Equation 4]

[0117]

[0118] - Matrix B k The final layer, which includes , can maintain the existing number of parity bits as needed.

[0119] - The increase or decrease in parity bits caused by the code rate adjustment in the first layer including matrix B1 can be compensated for by reducing the number of parity bits in the intermediate layers, as in [Mathematical Formula 5] below.

[0120] [Equation 5]

[0121]

[0122] - Through this, the overall sum maintenance condition of [Mathematical Formula 5] can be satisfied, and the condition for the increment / decrement sequence can be organized as in [Mathematical Formula 6] below.

[0123] [Equation 6]

[0124]

[0125] In the above method 2, for specific linear codes (e.g., LDPC codes in NR systems), it is possible to fix the number of information bits in each layer and only adjust the number of parity bits. In this case, consistency is maintained between the encoder in the transmitting device and the decoder in the receiving device, ensuring system simplicity. Furthermore, method 2 can improve overall decoding performance by protecting specific layers (e.g., the first or last layer) that are vulnerable to errors in staircase codes, thereby preventing error propagation in advance.

[0126] As an optional embodiment, the increment / decrement sequence described in [Equation 6] can have, for example, four options (i.e., additional methods for code rate control at each floor of the staircase code) through the two bits (XX) following "CodeRateForStairs" in the control information indicating the code rate control method. (In this case, the two bits in front of "CodeRateForStairs" are indicated as "01" to indicate code rate adjustment method 2.) For example, the code rate control methods that can be selected / indicated according to the two bits (XX) following "CodeRateForStairs" = 01XX are as follows: In this case, an increase in the number of parity bits leads to a decrease in the code rate, and as a result, the decoding capability can be improved.

[0127] - In the case of XX = 00: By reducing the code rate of the first layer of the staircase code, maintaining the code rate of the last layer, and increasing the code rates of the intermediate layers, the decrease in the code rate of the first layer can be compensated for in other layers as in [Mathematical Formula 7] below.

[0128] [Equation 7]

[0129]

[0130] - In the case of XX = 01: As in [Mathematical Formula 8] below, the decoding ability for the D preceding layers can be improved by reducing the code rate for the D preceding layers in the staircase code and increasing the code rate for the remaining (kD) succeeding layers.

[0131] [Equation 8]

[0132]

[0133] Here, the value of D can use a previously preset value, and the option of XX = 01 assumes that decryption starts from the first layer.

[0134] - In the case of XX = 10: This is the opposite of the case of XX = 00. In this case, the decrease in the code rate of the last layer can be compensated for by reducing the code rate of the last layer, maintaining the code rate of the first layer, and increasing the code rates of the intermediate layers, as in [Mathematical Formula 9] below.

[0135] [Equation 9]

[0136]

[0137] The above case of XX = 10 can be applied when decoding of the staircase code starts from the last layer.

[0138] - In the case of XX = 11: As in [Mathematical Formula 10] below, by reducing the code rate for D number of subsequent layers in the staircase code and increasing the code rate for the remaining (kD) preceding layers, the decoding ability for D number of subsequent layers can be improved.

[0139] [Equation 10]

[0140]

[0141] Here, the value of D can be a previously preset value, and the option of XX = 11 assumes that decoding of the staircase code starts from the last layer.

[0142] In the code rate control method of the present disclosure, the method of controlling the increment / decrease sequence is not limited to the four methods exemplified by XX = 00, 01, 10, 11, and the increment / decrease sequence can be expressed in various ways by extending the number of sequence bits of the control information to 4 bits or more.

[0143] [Example 3: Fixed , variable r i, Using LDPC codes as element codes]

[0144] Embodiment 3, like Embodiment 2, utilizes the code rate control method of the present disclosure in a step code, but can be applied when the element code uses an LDPC code in an NR system. As described above, in an NR system, the number of information bits in each layer of the LDPC code can be fixed, for example, and only the number of parity bits can be adjusted. In this case, new information bits are added to each layer of the step code. The number of bits remains the same, and the parity bits r i The code rate of the staircase code can be adjusted by changing only the number of bits. In this case, consistency is maintained between the encoder in the transmitting device and the decoder in the receiving device, ensuring simplicity in the system. When the length of the information to be transmitted in the transmitting device and the parity-check matrix (PCM) for encoding / decoding the information are defined, the number of rows and columns of the parity-check matrix is ​​adjusted to determine the number of parity bits r. i can be adjusted.

[0145] FIG. 11 is a diagram showing an example of a code rate control method when an LDPC code is used as an element code in a step code in an embodiment of the present disclosure.

[0146] Referring to Fig. 11, the size of the parity check matrix can be increased by adding one row and one column together whenever the number of bits corresponding to the "nonzero entry" in the parity parity check matrix for encoding / decoding information bits of a specific length K increases by one. The area where the bits corresponding to the "nonzero entry" in the parity parity check matrix of Fig. 11 exist is the part shaded as "nonzero entry" in Fig. 11, and the empty area can be filled with a matrix corresponding to 0, for example. When an LDPC code is used as an element code as in the example of Fig. 11, the number of information bits in each layer of the staircase code is maintained the same, and the code rate of the staircase code can be adjusted in such a way that only the number of parity bits changes.

[0147] FIG. 12 is a diagram showing an example of a code rate control method when an LDPC code is used as an element code in a step code in an embodiment of the present disclosure.

[0148] The example of Fig. 12 shows examples of layers (1211, 1212, 1213) composed of encoded element codewords by adjusting the code rate of the staircase code in such a way that the number of information bits in each layer of the staircase code is kept the same and only the number of parity bits is varied when using an LDPC code as an element code, as in the example of Fig. 11. In Fig. 12, the area where bits corresponding to "nonzero entries" in the parity parity check matrix exist is depicted with the same shade for convenience of explanation.

[0149] [Example 4: Variable , fixed r i ]

[0150] Example 4 is the opposite of Example 2 and Example 3 in that the number of new information bits can be varied, and the number of parity bits r iis a fixed case. As in Example 1, the number of total information bits to be transmitted from the transmitting device is K. tot and the overall code rate R tot can be determined through the setting information (control information) of the above [Table 1]. Embodiment 4 adjusts the code rate to apply protection to the number of new information bits of the element codewords of the layer. to a predetermined value It can be reduced by more than the value, and the loss of code rate that occurs here can be compensated for from other layers.

[0151] As described in the embodiments of FIGS. 6 to 12 above, by controlling the code rate for each layer of the staircase code, the decoding capability of specific layers that are vulnerable to error occurrence in the staircase code or where error propagation occurs and affects the decoding capability of adjacent layers can be improved, and the overall decoding capability can be improved. Through this, improvement in error rate performance in the staircase code can be expected, and consistency can be maintained in the communication system by appropriately utilizing the characteristics of the component codes, and performance improvement can be expected without additional complexity, and signaling information (control information) for the code rate control method can also be efficiently transmitted and received.

[0152] FIG. 13A is a diagram illustrating an encoding method including rate control in a step code performed in a transmitting device of a wireless communication system according to an embodiment of the present disclosure. The encoding method for rate control may be performed using at least one of the embodiments of FIGS. 6 to 12. The step code of FIG. 13A may be applied to both a square matrix-based step code and a non-square matrix-based step code.

[0153] Referring to FIG. 13A, in step 1301, a transmitting device may transmit encoding-related configuration information (control information) (e.g., “CodeRateForStairs”) including code rate control of a staircase code described in the embodiments of FIGS. 6 to 12 to a receiving device. The configuration information (control information) may include control information indicating the code rate control method. In addition, the configuration information (control information) may include at least one of the parameters in [Table 1], or information indicating / indicating the at least one parameter, or information corresponding to the at least one parameter. If the transmitting device and the receiving device have previously stored or know the encoding-related parameters of the staircase code, step 1301 may be omitted. In addition, the encoding-related configuration information (control information) may be transmitted as a combination of at least one of RRC information, DCI, and MAC-CE.

[0154] In step 1302, the transmitting device may adjust the code rate of at least one layer among all layers of the staircase code (for example, the at least one layer may include a decoding starting layer) to be relatively lower than the remaining layers excluding the at least one layer, and may adjust the code rates of the remaining layers to keep the overall code rate constant. In addition, the transmitting device may adjust the code rate of the staircase code according to the method indicated among Embodiments 1 to 4 described in Methods 1 to 4 above based on encoding-related setting information (control information) including the code rate control.

[0155] In step 1303, the transmitting device performs row-by-row encoding or column-by-column encoding using element codes according to a code rate adjusted in each layer of the staircase code, adds the generated parity bits to the corresponding layer to generate an element codeword, and transmits a staircase codeword composed of a plurality of generated element codewords to the receiving device.

[0156] FIG. 13b is a diagram illustrating a decoding method including rate control in a step code performed in a receiving device of a wireless communication system according to an embodiment of the present disclosure. The decoding method for rate control may be performed using at least one of the embodiments of FIGS. 6 to 12. The step code of FIG. 13b may be applied to both square matrix-based step codes and non-square matrix-based step codes.

[0157] Referring to FIG. 13B, in step 1311, the receiving device may receive encoding-related configuration information for controlling the code rate of a staircase code from the transmitting device. The configuration information (control information) may include control information indicating the code rate control method. In addition, the configuration information (control information) may include at least one of the parameters in [Table 1], or information indicating / indicating the at least one parameter, or information corresponding to the at least one parameter. If the transmitting device and the receiving device have previously stored or know the encoding-related parameters of the staircase code, step 1311 may be omitted. In addition, the encoding-related configuration information (control information) may be transmitted as a combination of at least one of RRC information, DCI, and MAC-CE.

[0158] In step 1312, the receiving device can receive a step code word from the transmitting device, in which the decoding starting layer of the step code has a code rate adjusted to be relatively lower than that of the remaining layers. At this time, the step code word can have the code rate of the step code adjusted according to a method indicated among Embodiments 1 to 4 described in Methods 1 to 4 above, based on encoding-related setting information (control information) including the code rate control.

[0159] At step 1313, the receiving device can perform row-by-row decoding or column-by-column decoding on the received staircase code word according to the adjusted code rate at each layer of the staircase code to restore the information bits.

[0160] FIG. 14 is a diagram illustrating an example configuration of a communication device in a wireless communication system according to an embodiment of the present disclosure. The communication device may be a transmitting device that performs an encoding method including code rate control of the above-described step code, or a receiving device that performs a decoding method including code rate control of the above-described step code. In addition, the communication device of FIG. 14 may be either a base station or a terminal.

[0161] The communication device of FIG. 14 may include a processor (1401), a transceiver (1403), and a memory (1405). The processor (1401), the transceiver (1403), and the memory (1405) of the communication device may operate according to the encoding / decoding method including the code rate control of the staircase code described in the embodiments of FIGS. 6 to 13b. However, the components of the communication device are not limited to the examples described above. For example, the communication device may include more or fewer components than the components described above. In addition, the processor (1401), the transceiver (1403), and the memory (1405) may be implemented in the form of a single chip.

[0162] The transceiver (1403) is a general term for the receiver and transmitter of a communication device, and can transmit and receive signals with the counterpart communication device. At this time, the transmitted and received signals may include at least one of control information and data. In addition, the transceiver (1403) may receive a signal, output it to the processor (1401), and transmit the signal output from the processor (1401). In addition, the transceiver (1403) of FIG. 14 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. In addition, the transceiver (1403) may receive a signal, output it to the processor (1401), and transmit the signal output from the processor (1401) to the counterpart communication device via a network. The memory (1405) may store programs and data necessary for performing the encoding / decoding method, including the code rate control of the staircase code described in the embodiments of FIGS. 6 to 13B. The memory (1405) can store control information or data included in a signal acquired from the communication device. The memory (1405) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the processor (1401) can control a series of processes so that the communication device can operate according to at least one of the embodiments of FIGS. 1A to 13B. The processor (1401) can include at least one processor.

[0163] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software. If implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or specification of the present disclosure.

[0164] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies. The above program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. This storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0165] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0166] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method for encoding a step code performed in a transmitting device in a wireless communication system, A process of lowering a code rate in at least one layer among all layers of the above-mentioned staircase code to be relatively lower than the code rates of the remaining layers excluding the at least one layer, and adjusting the code rates of the remaining layers to maintain the overall code rate of the above-mentioned staircase code constant; A process of alternately performing row-by-row encoding or column-by-column encoding using element codes according to the adjusted code rate at each layer of the above-mentioned staircase code; and An encoding method comprising a process of transmitting a step code word generated by performing the row-by-row encoding or the column-by-column encoding to a receiving device.

2. In paragraph 1, An encoding method wherein at least one of the layers comprises a decoding starting layer from which decoding starts in the receiving device, the decoding starting layer being one of a first layer and a last layer of the staircase code.

3. In paragraph 1, It further includes a process of transmitting encoding-related control information for controlling the code rate of the above-mentioned step code to a receiving device, The above encoding-related control information is the number of new information bits in each layer of the staircase code ( ) and the number of parity bits (r i ) is fixed or variable, and the first bit information indicates one of the following methods 1 to 4 for code rate control in each layer (i): Method 1: Fixed , fixed r i = r Method 2: Fixed , variable r i Method 3: Variable , fixed r i = r Method 4: Variable , variable r i The above encoding related control information further includes second bit information indicating one of the following four options for encoding rate control in each layer of the staircase code, wherein the second bit information indicates an encoding method to be applied when the first bit information indicates method 2. Option 1: Reduce the code rate of the first layer in the above staircase code, maintain the code rate of the last layer, and increase the code rate of the intermediate layers. Option 2: In the above staircase code, decrease the code rate for the first D layers among the k layers and increase the code rate for the remaining (kD) layers. Option 3: Reduce the code rate of the last layer in the above-mentioned staircase code, maintain the code rate of the first layer, and increase the code rate of the intermediate layers. Option 4: In the above staircase code, decrease the code rate for the last D layers among the k layers and increase the code rate for the remaining (kD) preceding layers.

4. In paragraph 1, It further includes a process of transmitting encoding-related control information for controlling the code rate of the above-mentioned step code to a receiving device, The above encoding-related control information is the number of new information bits in each layer of the staircase code ( ) and the number of parity bits (r i ) contains the first bit information indicating whether it is fixed or variable, An encoding method wherein the above encoding-related control information further includes second bit information indicating one of a plurality of options related to an increase or decrease in a code rate for code rate control in each layer of the staircase code.

5. In paragraph 3, An encoding method in which, when using an LDPC (low density parity check) code as the above element code, the number of information bits in each layer of the staircase code is fixed and the code rate is adjusted by adjusting the number of parity bits.

6. In paragraph 3, An encoding method in which the above encoding-related control information is transmitted to the receiving device using a combination of at least one of RRC (radio resource control) information, DCI (downlink control information), and MAC-CE (medium access control-control element).

7. In a transmitting device that performs coding of a staircase code in a wireless communication system, Transmitter and receiver; and In at least one layer among all layers of the above-mentioned staircase code, the code rate is adjusted to be relatively lower than that of the remaining layers excluding the at least one layer, and the code rates of the remaining layers are adjusted to maintain the overall code rate of the above-mentioned staircase code constant. In each layer of the above-mentioned staircase code, row-by-row encoding or column-by-column encoding is performed alternately using element codes according to the adjusted code rate. A transmitting device including a processor configured to transmit, to a receiving device, a staircase code word generated by performing the row-by-row encoding or the column-by-column encoding through the transceiver.

8. A transmitter according to claim 7, adapted to operate according to any one of the methods of claims 2 to 6.

9. In a method for decoding a step code performed in a receiving device in a wireless communication system, A process of receiving a step code code word from a transmitting device, the code rate of which is adjusted to be relatively lower in at least one layer among all layers of the step code than in the remaining layers excluding the at least one layer; and A decoding method including a process of restoring information bits by performing row-by-row decoding or column-by-column decoding using element codes according to a code rate adjusted at each layer of the above-described received staircase code word.

10. In paragraph 9, A decryption method wherein at least one of the layers comprises a decryption starting layer from which decryption starts in the receiving device, the decryption starting layer being one of a first layer and a last layer of the staircase code.

11. In paragraph 9, It further includes a process of receiving encoding-related control information for controlling the code rate of the step code from the transmitting device, The above encoding-related control information is the number of new information bits in each layer of the staircase code ( ) and the number of parity bits (r i ) is fixed or variable, and the first bit information indicates one of the following methods 1 to 4 for code rate control in each layer (i): Method 1: Fixed , fixed r i = r Method 2: Fixed , variable r i Method 3: Variable , fixed r i = r Method 4: Variable , variable r i The above encoding-related control information further includes second bit information indicating one of the following four options for code rate control in each layer of the staircase code, wherein the second bit information indicates a decoding method to be applied when the first bit information indicates method 2. Option 1: Reduce the code rate of the first layer in the above staircase code, maintain the code rate of the last layer, and increase the code rate of the intermediate layers. Option 2: In the above staircase code, decrease the code rate for the first D layers among the k layers and increase the code rate for the remaining (kD) layers. Option 3: Reduce the code rate of the last layer in the above-mentioned staircase code, maintain the code rate of the first layer, and increase the code rate of the intermediate layers. Option 4: In the above staircase code, decrease the code rate for the last D layers among the k layers and increase the code rate for the remaining (kD) preceding layers.

12. In paragraph 9, It further includes a process of receiving encoding-related control information for controlling the code rate of the step code from the transmitting device, The above encoding-related control information is the number of new information bits in each layer of the staircase code ( ) and the number of parity bits (r i ) contains the first bit information indicating whether it is fixed or variable, A decoding method wherein the above encoding-related control information further includes second bit information indicating one of a plurality of options related to an increase or decrease in the encoding rate for encoding rate control in each layer of the staircase code.

13. In a receiving device that performs decoding of a staircase code in a wireless communication system, Transmitter and receiver; and A step code code word having a code rate adjusted to be relatively lower than that of the remaining layers excluding the at least one layer among all layers of the step code is received from a transmitting device through the transceiver, A receiving device including a processor configured to restore information bits by performing row-by-row decoding or column-by-column decoding using element codes according to a code rate adjusted at each layer of the stepped code for the received stepped code code word.

14. A receiving device according to claim 13, adapted to operate according to any one of the methods of claims 10 to 12.

Images