Layered LDPC Decoding Using Reduced-Node Syndrome Checks

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Solution Overview

Problem

Current LDPC code decoding methods in wireless communication systems face challenges with high power consumption and latency, particularly in achieving low error rates and low latency radio requirements, especially in future-generation communication systems.

Innovation Solution

A method for layered decoding of LDPC codes that reduces memory reads, power consumption, and latency by optimizing the updating and syndrome check processes, specifically by modifying the relational expressions for syndrome value calculation to minimize the number of variable nodes connected to each check node and using a hierarchical decoding approach.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional LDPC decoding methods are used to achieve low error rates, then reliability is improved, but power consumption and latency increase

Engineering Contradiction:
Improveerror rateVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The decoding process is divided into multiple layers where variable nodes are processed in sequential groups rather than all at once. Each layer updates a subset of variable nodes based on check node syndromes, allowing the decoder to make progress toward error correction while consuming less power per iteration and reducing overall decoding latency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The decoding algorithm dynamically adjusts the updating order of variable nodes across different layers based on syndrome information. This dynamic approach allows the system to focus computational resources on the most critical error patterns first, improving reliability while optimizing power consumption by avoiding unnecessary updates to already-corrected nodes.

Inventive Principle:
Principle #15Dynamics

2Reliability

If conventional LDPC decoding methods are used to achieve low error rates, then reliability is improved, but latency increases

Engineering Contradiction:
Improveerror rateVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

By segmenting the variable nodes into multiple layers and processing them sequentially, the decoder achieves low error rates through systematic error correction while reducing latency. The layered structure allows early termination when syndromes become zero, avoiding the need to process all variable nodes in every iteration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The algorithm performs preliminary syndrome checks before completing full variable node updates. If syndromes are already zero after processing some layers, the decoding can terminate early, significantly reducing latency while maintaining reliability by ensuring all necessary error corrections have been applied.

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If the number of variable nodes connected to each check node is minimized for syndrome calculation, then power consumption and latency are reduced, but decoding complexity increases

Engineering Contradiction:
Improvepower consumptionVSAvoiddecoding complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

Variable nodes are segmented into layers with controlled connectivity to check nodes. Each layer is designed to update a specific subset of variable nodes based on syndrome requirements, reducing the number of connections per check node while maintaining decoding capability. This segmentation lowers power consumption by limiting the active node set at each step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connectivity between variable nodes and check nodes is dynamically adjusted across layers. The updating order and connection patterns are optimized to minimize simultaneous active connections, reducing power consumption. The dynamic reconfiguration of the decoding graph across layers manages complexity by processing nodes in manageable groups rather than all at once.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3595203B1Layered decoding method for LDPC code and device therefor
Publication Date: 2021.11.10 LG ELECTRONICS INC
  • EP3595203B1 patent drawingFigure 1
  • EP3595203B1 patent drawingFigure 2
  • EP3595203B1 patent drawingFigure 3

AI summary

An improved layered decoding method for a low density parity check (LDPC) code and a device therefor are disclosed. Disclosed is the layered decoding method for an LDPC code, capable of determining whether decoding is successful by performing a syndrome check on each check node at every variable node update. In addition, the syndrome check can be performed by using reduced variable nodes, thereby reducing decoding power consumption and decoding time consumption.