# US 2020/0403635 A1 · Decoding system and decoding method

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- Number: US 2020/0403635 A1
- Document ID: US20200403635A1
- Status: Published application
- Kind: A1
- Application number: 16/446,758
- Filed: 2019-06-20
- Published: 2020-12-24
- Earliest claimed: 2019-06-20
- Assignees: Macronix International Co., Ltd.
- Applicants: Macronix International Co., Ltd.
- Inventors: Yu-Ming HUANG; Hsi-Chia CHANG
- Web page: https://patentgrep.com/patent/US20200403635A1

## CPC

- H03M 13/09: Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
- H03M 13/1125: {using different domains for check node and bit node processing, wherein the different domains include probabilities, likelihood ratios, likelihood differences, log-likelihood ratios or log-likelihood difference pairs}
- H03M 13/13: Linear codes
- H03M 13/2906: {using block codes (H03M13/2957 takes precedence)}
- H03M 13/43: Majority logic or threshold decoding
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

The present disclosure provides a decoding system and method. The decoding system comprises a first decoder and a second decoder. The first decoder is configured to generate an intermediate decoding data by decoding a code data. The second decoder, coupled to the first decoder, wherein the second decoder is configured to generate a plain data by decoding the intermediate decoding data.

## Claims

### Claim 1

A decoding system, comprising:
a first decoder, configured to generate an intermediate decoding data by decoding a code data according to a list having a variable list size in a first decoding algorithm; and
a second decoder, coupled to the first decoder, wherein the second decoder is configured to generate a plain data by decoding the intermediate decoding data in a second decoding algorithm;
wherein the first decoder is further configured to:
decode the code data by using a polar code and execute a decoding procedure of the polar code which generates a decoding tree comprising a plurality of levels;
determine the variable list size according to an error rate of each of the plurality of levels; and
obtain the intermediate decoding data according to the variable list size, wherein each of the intermediate decoding data comprises a plurality of candidate data and a number of the plurality of candidate data is equal to the variable list size.

### Claim 2

(canceled)

### Claim 3 (depends on 1)

The decoding system of claim 1, wherein the plurality of levels comprises a first level and a second level and the first level comprises a first number of nodes and the second level comprises a second number of nodes, wherein the first decoder is further configured to:
reduce the variable list size in response to the error rate of the first level being less than an error threshold; and
keep the candidate data, which number is equal to the variable list size which is reduced, from the nodes of the first level.

### Claim 4 (depends on 3)

The decoding system of claim 3, wherein the first decoder is further configured to:
increase the variable list size in response to the error rate of the first level being larger than the error threshold; and
keep the candidate data, which number is equal to the variable list size which is increased, from the nodes of the second level.

### Claim 5 (depends on 1)

The decoding system of claim 1, wherein each of the candidate data comprises a redundancy data corresponding to a cyclic redundancy check (CRC) code, and the second decoder is further configured to filter the candidate data by using the redundancy data of each of the candidate data, and to choose the candidate data which passes an error detection check of the CRC code.

### Claim 6 (depends on 5)

The decoding system of claim 5, wherein the second decoder is further configured to remove the redundancy data of the candidate data which is chosen in order to generate the plain data.

### Claim 7 (depends on 5)

The decoding system of claim 5, wherein the decoding procedure comprises a successive cancellation list decoding procedure, wherein the first decoder is further configured to execute the successive cancellation list decoding procedure to generate a plurality of decoding paths where each of the plurality of decoding path comprises the candidate data in a first level and the candidate data in a second level, wherein each of the decoding paths comprises a correct probability.

### Claim 8 (depends on 7)

The decoding system of claim 7, wherein the first decoder is configured to select a decode path which comprises a highest correct probability from the decoding paths.

### Claim 9 (depends on 1)

The decoding system of claim 1, further comprising:
an applied device, coupled to the first decoder, wherein the applied device is configured to output the code data to the first decoder.

### Claim 10

A decoding method, suitable for a decoding system comprising a first decoder and a second decoder coupled to the first decoder, wherein the decoding method comprises:
generating, by the first decoder, an intermediate decoding data by decoding a code data according to a list having a variable list size in a first decoding algorithm;
generating, by the second decoder, a plain data by decoding the intermediate decoding data in a second decoding algorithm;
decoding, by the first decoder, the code data by using a polar code and executing a decoding procedure of the polar code which generates a decoding tree comprising a plurality of levels;
determining, by the first decoder, the variable list size according to an error rate of each of the plurality of levels; and
obtaining the intermediate decoding data according to the variable list size, wherein each of the intermediate decoding data comprises a plurality of candidate data and a number of the plurality of candidate data is equal to the variable list size.

### Claim 11

(canceled)

### Claim 12 (depends on 10)

The decoding method of claim 10, wherein the plurality of levels comprises a first level and a second level and the first level comprises a first number of nodes and the second level comprises a second number of nodes, wherein the decoding method further comprises:
reducing the variable list size in response to the error rate of the first level being less than an error threshold; and
keeping the candidate data, which number is equal to the variable list size which is reduced, from the nodes of the first level.

### Claim 13 (depends on 12)

The decoding method of claim 12, further comprising:
increasing the variable list size in response to the error rate of the first level being more than the error threshold; and
keeping the candidate data, which number is equal to the variable list size which is increased, from the nodes of the second level.

### Claim 14 (depends on 10)

The decoding method of claim 10, wherein each of the candidate data comprises a redundancy data corresponding to a cyclic redundancy check (CRC) code, and the decoding method further comprises:
filtering, by the second decoder, the candidate data by using the redundancy data of each of the candidate data; and
choosing, by the second decoder, the candidate data which passes an error detection check by the CRC code.

### Claim 15 (depends on 14)

The decoding method of claim 14, further comprising:
removing, by the second decoder, the redundancy data of the candidate data which is chosen in order to generate the plain data.

### Claim 16 (depends on 14)

The decoding method of claim 14, further comprising:
executing, by the first decoder, a successive cancellation list decoding procedure to generate a plurality of decoding paths where each of the plurality of decoding path comprises the candidate data in a first level and the candidate data in a second level, wherein each of the decoding paths comprises a correct probability.

### Claim 17 (depends on 16)

The decoding method of claim 16, further comprising:
selecting a decode path which comprises a highest correct probability from the decoding paths.