Apparatus and method for decoding successive cancellation list of polar codes by using power gating

Abstract

Provided are an apparatus and method for decoding a successive cancellation list of polar codes by using power gating. The apparatus for decoding a successive cancellation list of polar codes by using power gating according to an embodiment comprises: a plurality of successive cancellation list decoding units that receive polar-encoded codes and decode the codes by using a successive cancellation list technique; and a power gating circuit unit that is connected to a preset number of successive cancellation list decoding units among the plurality of successive cancellation list decoding units and controls the supply of current.

Description

Device and method for decoding a list of consecutively removed polar codes using power gating

[0001] Embodiments of the present invention relate to a technique for decoding a continuous removal list of polar codes using power gating.

[0002]

[0003] Polar codes are the first error-correcting codes capable of achieving channel capacity on discrete memoryless channels. Polar codes utilize the Successive Cancellation (SC) algorithm as their primary decoding method, but they have drawbacks. Compared to low-density parity-check (LDPC) codes and turbo codes, they exhibit lower error-correcting performance.

[0004] To improve these shortcomings, several decoding methods have been proposed to improve error correction performance based on the continuous elimination algorithm. One of them is the continuous elimination list (SC List; SCL) decoding method. The SCL decoding method is basically the same as the SC decoding method, but the number of bits is a power of 2 (L = 2). l, l = 1, 2, 3, ...) exist. The number of these paths is the list size of SCL decoding. In the SCL decoding method, each path performs SC decoding individually, and the bits decoded in each path are stored to obtain the final codeword decoded in the corresponding path. In the SCL decoding method, each path is copied into two paths each time one information bit is decoded. That is, as the decoding progresses, the L paths increase to 2L, and the L paths with the highest reliability are selected again through the path selection process. When all bits are decoded, a cyclic redundancy check (CRC) is performed on the result of each path, and the codeword of the path that passes the CRC is output as the final decoded result. If this SCL decoding method is used, the low error correction performance of the SC decoding method can be improved.

[0005] In other words, the SCL decoding method can decode polar codes with improved error correction performance. However, the SCL decoding method has the disadvantage of requiring approximately L times (the size of the list) more computational effort than the conventional SC decoding method.

[0006]

[0007] Embodiments of the present invention provide a device and method for decoding a continuous removal list of polar codes using power gating.

[0008]

[0009] According to an exemplary embodiment of the present invention, a power gating-based successive cancellation list decoding device for polar codes is provided, comprising: a plurality of successive cancellation list decoding units that receive a polar encoded codeword and decode the codeword using a successive cancellation list technique; and a power gating circuit unit that is connected to a preset number of successive cancellation list decoding units among the plurality of successive cancellation list decoding units and controls current supply.

[0010] The power gating circuit may further include a signal generation unit that generates a power signal according to a preset condition; and a current control unit that increases or decreases the gate voltage of a sleep transistor according to the generated power signal to control the current supply to the continuous removal list decoding unit of the preset number.

[0011] The signal generation unit can generate a first power signal to block the current supply to the predetermined number of consecutive removal list decoding units during the decoding process when the plurality of consecutive removal list decoding units receive the codeword.

[0012] The signal generation unit can generate a second power signal to block the current supply to a preset number of consecutive removal list decoding units during a preset section during a decoding process when the plurality of consecutive removal list decoding units receive the codeword.

[0013] The signal generation unit may generate the second power signal so that, when the plurality of continuous removal list decoding units receive the codeword, the second power signal extracts a Rate-1 node from the codeword and, during the decoding process, cuts off the current supply to the predetermined number of continuous removal list decoding units in a section corresponding to the Rate-1 node.

[0014]

[0015] According to embodiments of the present invention, by using power gating in the SCL (Successive Cancellation List) decoding method, there is an effect of improving error correction performance while reducing the computational amount and power consumption of the SCL decoding method, which is L times higher than that of the existing SC decoding method.

[0016]

[0017] FIG. 1 is a drawing for explaining a continuous removal list encoding-decoding device of a polar code according to one embodiment of the present invention.

[0018] FIG. 2 is a drawing for explaining a device for decoding a list of consecutive removals of polar codes using power gating according to one embodiment of the present invention.

[0019] FIG. 3 is a drawing for explaining the operation method of a decoding device for a continuous removal list of polar codes using power gating according to one embodiment of the present invention.

[0020] FIG. 4 is a drawing for explaining the operation method of a decoding device for a continuous removal list of polar codes using power gating according to another embodiment of the present invention.

[0021] Figure 5 is a graph comparing error correction performance according to the decoding device of the polar code.

[0022] FIG. 6 is a diagram showing a reduction rate in the amount of computation of a decoding device for a continuous removal list of polar codes using power gating according to disclosed embodiments.

[0023] FIG. 7 is a block diagram illustrating a computing environment including a computing device according to one embodiment.

[0024]

[0025] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, devices, and / or systems described herein. However, these are merely examples and the present invention is not limited thereto.

[0026] In describing embodiments of the present invention, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and this may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing embodiments of the present invention and should not be limited in any way. Unless clearly used otherwise, the singular form includes the plural form. In this description, expressions such as "comprises" or "having" are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, parts or combinations thereof other than those described.

[0027] Meanwhile, embodiments of the present invention may include a program for performing the methods described herein on a computer, and a computer-readable recording medium including the program. The computer-readable recording medium may include program commands, local data files, local data structures, etc., alone or in combination. The medium may be specially designed and configured for the present invention, or may be one commonly used in the field of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and hardware devices specially configured to store and execute program commands such as ROMs, RAMs, and flash memories. Examples of the program may include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0028]

[0029] FIG. 1 is a drawing for explaining a continuous removal list encoding-decoding device of a polar code according to one embodiment of the present invention.

[0030] Referring to FIG. 1, the present invention can explain a polar encoding device (1) and a successive cancellation list decoding device (2) used in a communication system as an example. The polar encoding device (1) can encode data (information bits) to be transmitted through a polar encoding unit (5) and transmit the encoded data (codeword) to a successive cancellation list decoding device (3) through a channel (2). Here, the polar code is a code that achieves channel capacity by utilizing the channel polarization phenomenon that occurs when multiple channels are combined and then appropriately separated. In addition, the successive cancellation list decoding device (3) can decode the codeword received from the polar encoding device (1) through the channel (2) through a successive cancellation list (SCL) decoding technique through a successive cancellation list decoding unit (6) to estimate and output the data encoded by the polar encoding device (1). At this time, the CRC encoding unit (4) of the polar encoding device (1) is processed to generate a CRC code, and the CRC code of the result value generated through the CRC decoding unit (7) of the continuous removal list decoding device (3) is compared with the CRC code generated by the CRC encoding unit (4) to check whether an error has occurred in the data. If there is no error after checking whether an error has occurred, the data is output.

[0031] This continuous removal list decryption device (2) is composed of L (list size) continuous removal list decryption units (6) that operate simultaneously and in parallel. At this time, the continuous removal list decryption device (2) composed of L continuous removal list decryption units (6) requires an area and computational volume that is approximately L times larger than that of the existing continuous removal decryption device. In particular, the computational volume is directly related to power consumption, and thus consumes approximately L times more power than the continuous removal decryption device.

[0032] The present invention provides a method for reducing the amount of computation and power consumption of a polar code continuous removal list decoding device (100) by controlling the power supply of some of the L continuous removal list decoding units (200) using power gating.

[0033]

[0034] FIG. 2 is a drawing for explaining a device for decoding a list of consecutive removals of polar codes using power gating according to one embodiment of the present invention.

[0035] Referring to FIG. 2, a device (100) for decoding a continuous removal list of polar codes using power gating according to one embodiment may include a continuous removal list decoding unit (200) and a power gating circuit unit (300).

[0036] In the embodiments below, each component may have different functions and capabilities other than those described below, and may include additional components other than those described below.

[0037] In addition, in the following embodiments, the continuous removal list decryption unit (200) and the power gating circuit unit (300) may be implemented using one or more physically separated devices, or may be implemented by a combination of one or more processors or one or more processors and software, and may not be clearly distinguished in specific operations, unlike the illustrated example.

[0038] The continuous removal list decryption unit (200) can decrypt the received codeword using the continuous removal list method.

[0039] Meanwhile, the successive cancellation list method used in the present invention is a well-known technology, so a detailed description will be omitted. However, to briefly explain, the successive cancellation list decoding device is a decoding method proposed by Tal and Vardy in 2011, and is a decoding method that improves the performance of the existing successive cancellation (SC) decoding of polar codes.

[0040] The power gating circuit (300) can control the current supply to the continuous removal list decoding unit (200). In addition, the power gating circuit (300) can include a signal generation unit (310), a sleep transistor (320), and a current control unit (330). The power gating circuit (310) can control the current supply to the continuous removal list decoding unit (200) by having the current control unit (330) increase or decrease the gate voltage of the sleep transistor (320) according to a power signal generated by the signal generation unit (310). For example, in the active mode, the sleep transistor (320) is in a linear region, so the gate VSS has a value close to VSS. On the other hand, in the sleep mode, the sleep transistor (320) is turned off, so the gate VSS has a value close to VDD. At this time, the power gating circuit (300) may be connected to a preset number of continuous removal list decryption units (200). For example, the power gating circuit (320) may be connected to four of the eight continuous removal list decryption units (200).

[0041] The signal generation unit (310) can generate a power signal according to preset conditions. A detailed description thereof will be provided with reference to FIGS. 3 and 4 below.

[0042]

[0043] FIG. 3 is a diagram for explaining an operation method of a decoding device for decoding a list of consecutive removals of polar codes using power gating according to one embodiment of the present invention.

[0044] Referring to FIG. 3, a device (100) for decoding a continuous elimination list of polar codes using power gating according to one embodiment can, when a codeword having a total code length of 8 bits is received, cut off the current supply to a preset number of decoding units during the decoding process. Here, the codeword can be composed of information bits and frozen bits. At this time, when the continuous elimination list decoding unit (200) receives the codeword, the signal generation unit (310) can generate a power signal so as to cut off the current supply to a preset number of continuous elimination list decoding units (200). For example, by blocking the current supply to M (e.g., 2) consecutive removal list decryption units (200-3, 200-4) while decrypting among L (e.g., 4) consecutive removal list decryption units (200-1, 200-2, 200-3, 200-4), the amount of computation and power consumption can be reduced in proportion to M / L. Here, L may refer to the total number of consecutive removal list decryption units (200), and M may refer to the number of consecutive removal list decryption units (200) to which a power gating circuit is applied.

[0045] That is, the continuous removal list decoding device (100) using power gating according to one embodiment can select an error correction performance priority mode or a power efficiency priority mode by applying a power gating circuit to a certain number of continuous removal list decoding units (200).

[0046]

[0047] FIG. 4 is a diagram for explaining the operation method of a decoding device for decoding a list of consecutive removals of polar codes using power gating according to another embodiment of the present invention.

[0048] Referring to FIG. 4, a device (100) for decoding a polar code's continuous elimination list using power gating according to one embodiment may, when receiving a codeword having a total code length of 8 bits, cut off the current supply to a preset number of continuous elimination list decoding units (200) in a preset section while performing decoding. Here, the codeword may be composed of information bits and frozen bits. In addition, the preset section may be a decoding section of a Rate-1 node. A Rate-1 node may mean a node composed of information bits that are concatenated to a certain length or more. Here, a section including the 7th and 8th bits, a section including the 11th and 12th bits, and a section including the 13th to 16th bits may be Rate-1 nodes.

[0049] At this time, when the continuous removal list decoding unit (200) receives a codeword, the signal generation unit (310) can extract a Rate-1 node and generate a power signal to block the current supply to a preset number of continuous removal list decoding units (200) in the section corresponding to the Rate-1 node during the decoding process. For example, while decoding is in progress among L continuous removal list decoding units (200-1, 200-2, 200-3, 200-4), the current supply to M continuous removal list decoding units (200-3, 200-4) in the section corresponding to the Rate-1 node can be blocked.

[0050] That is, since the decoding path splitting and pruning in the SCL decoding process is performed on information bits, the amount of computation and power consumption can be reduced by cutting off power to a predetermined number of consecutive removal list decoding units (200) at nodes (Rate-1) composed of information bits that are concatenated to a certain length or more.

[0051]

[0052] FIG. 5 is a graph comparing error correction performance according to a polar code decoding device, and FIG. 6 is a diagram showing a reduction rate in the amount of computation of a polar code continuous removal list decoding device using power gating according to the disclosed embodiments.

[0053] Referring to FIGS. 5 and 6, when decoding a polar code using a continuous removal list decoding device (100) using power gating according to an embodiment of the present invention, although there is a deterioration in error correction performance compared to the same list size, the amount of computation can be reduced compared to the same list size, thereby reducing power consumption. For example, it can be confirmed that SCL 8-4 has a deterioration in error correction performance compared to SCL 8, but the error correction performance is improved compared to SCL 4, and it can be confirmed that SCL 8-4 has a 19% reduction in computation compared to SCL 8. Here, SCL 8-4 may mean that power gating is applied to four of the eight consecutive removal list decryption units (200), and SCL 4-2 may mean that power gating is applied to two of the four consecutive removal list decryption units (200).

[0054] That is, when only some of the continuous removal list decoding units (200) are used in the continuous removal list decoding device (100) of the polar code, compared to the case where all of the continuous removal list decoding units (200) are operated, there is a deterioration in error correction performance, but the effect of a reduction in the amount of computation and a reduction in power consumption due to this can be confirmed.

[0055]

[0056] FIG. 7 is a block diagram illustrating a computing environment (10) including a computing device (12) according to one embodiment.

[0057] In the illustrated embodiment, each component may have different functions and capabilities other than those described below, and may include additional components other than those described below.

[0058] The illustrated computing environment (10) includes a computing device (12). In one embodiment, the computing device (12) may be one or more components included in a continuous removal list decryption device (100) of polar codes using power gating.

[0059] A computing device (12) includes at least one processor (14), a computer-readable storage medium (16), and a communication bus (18). The processor (14) may cause the computing device (12) to operate according to the exemplary embodiments mentioned above. For example, the processor (14) may execute one or more programs stored in the computer-readable storage medium (16). The one or more programs may include one or more computer-executable instructions, which, when executed by the processor (14), may be configured to cause the computing device (12) to perform operations according to the exemplary embodiments.

[0060] A computer-readable storage medium (16) is configured to store computer-executable instructions or program code, program data, and / or other suitable forms of information. A program (20) stored in the computer-readable storage medium (16) includes a set of instructions executable by the processor (14). In one embodiment, the computer-readable storage medium (16) may be a memory (volatile memory such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, any other form of storage medium that can be accessed by the computing device (12) and store desired information, or a suitable combination thereof.

[0061] A communication bus (18) interconnects various other components of the computing device (12), including the processor (14) and computer-readable storage media (16).

[0062] The computing device (12) may also include one or more input / output interfaces (22) and one or more network communication interfaces (26) that provide interfaces for one or more input / output devices (24). The input / output interfaces (22) and the network communication interfaces (26) are connected to the communication bus (18). The input / output devices (24) may be connected to other components of the computing device (12) via the input / output interfaces (22). Exemplary input / output devices (24) may include input devices such as pointing devices (such as a mouse or a trackpad), a keyboard, a touch input device (such as a touchpad or a touchscreen), a voice or sound input device, various types of sensor devices and / or photographing devices, and / or output devices such as display devices, printers, speakers and / or network cards. The exemplary input / output devices (24) may be included within the computing device (12) as a component constituting the computing device (12), or may be connected to the computing device (12) as a separate device distinct from the computing device (12).

[0063]

[0064] While representative embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications to the above-described embodiments are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims set forth below but also by equivalents thereof.

Claims

1. A plurality of successive cancellation list decoding units that receive a polar encoded codeword and decode the codeword using a successive cancellation list technique; and A polar code continuous removal list decoding device using power gating, comprising a power gating circuit connected to a preset number of continuous removal list decoding units among the plurality of continuous removal list decoding units and controlling current supply.

2. In claim 1, The above power gating circuit part, A signal generation unit that generates a power signal according to preset conditions; and A polar code continuous removal list decoding device using power gating, further comprising a current control unit that controls the current supply to the predetermined number of continuous removal list decoding units by increasing or decreasing the gate voltage of the sleep transistor according to the generated power signal.

3. In claim 2, The above signal generating unit, A polar code continuous elimination list decoding device using power gating, which generates a first power signal to block the current supply to the predetermined number of continuous elimination list decoding units during the decoding process when the plurality of continuous elimination list decoding units receive the codeword.

4. In claim 2, The above signal generating unit, A polar code continuous elimination list decoding device using power gating, which generates a second power signal to block the current supply to a preset number of continuous elimination list decoding units during a preset section during a decoding process when the plurality of continuous elimination list decoding units receive the codeword.

5. In claim 4, The above signal generating unit, A polar code continuous elimination list decoding device using power gating, which extracts a Rate-1 node from the code word when the plurality of continuous elimination list decoding units receive the code word, and generates the second power signal to block the current supply to the predetermined number of continuous elimination list decoding units in the section corresponding to the Rate-1 node during the decoding process.

6. One or more processors, and A method for decrypting a list of consecutive removals of polar codes using power gating, performed in a computing device having a memory storing one or more programs executed by one or more processors, A step of generating a power signal according to preset conditions; and A method for decoding a polar code's continuous elimination list using power gating, comprising a step of controlling current supply to a plurality of continuous elimination list decoding units by increasing or decreasing the gate voltage of a sleep transistor according to the generated power signal.

7. In claim 6, The step of generating the above power signal is: A method for decoding a polar code's continuous elimination list using power gating, wherein when the plurality of continuous elimination list decoding units receive a codeword, a first power signal is generated to block the current supply to a preset number of continuous elimination list decoding units among the plurality of continuous elimination list decoding units during the decoding process.

8. In claim 6, The step of generating the above power signal is: A method for decoding a polar code consecutive elimination list using power gating, wherein when the plurality of consecutive elimination list decoding units receive a codeword, a second power signal is generated to block the current supply to a preset number of consecutive elimination list decoding units among the plurality of consecutive elimination list decoding units during a preset section during the decoding process.

9. In claim 8, The step of generating the above power signal is: When the plurality of consecutive removal list decryption units receive the codeword, a step of extracting a Rate-1 node from the codeword; and A method for decoding a continuous removal list of polar codes using power gating, further comprising a step of generating the second power signal to block the current supply to the continuous removal list decoding unit of the preset number in the section corresponding to the Rate-1 node during the decoding process.

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