LDPC Decoder Iteration Control Under Buffer and Time Constraints

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Solution Overview

Problem

Current LDPC decoding systems face inefficiencies due to a fixed number of iterations for decoding data packets, which can lead to inadequate decoding performance for varying signal quality and limited available decoding time or buffer space.

Innovation Solution

A dynamic iteration control method that adjusts the number of decoding iterations based on available decoding time and input buffer space, allowing for more iterations when resources are sufficient and reducing them when resources are limited, to optimize decoding performance and prevent packet loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed number of iterations is used for decoding all data packets, then the decoding process is simple to implement, but decoding performance becomes inadequate for varying signal quality and the system cannot adapt to different available decoding times

Engineering Contradiction:
Improvedecoding performance adaptationVSAvoiditeration control complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic iteration control where the number of decoding iterations is adjusted in real-time based on available decoding time and buffer space. The iteration controller modifies the fixed iteration count dynamically, allowing the system to adapt to varying signal qualities and resource availability without requiring complex adaptive algorithms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the iteration parameter based on monitored conditions (buffer space and decoding time). By adjusting this single critical parameter, the system achieves adaptability to different operating conditions while maintaining relatively simple control logic, directly resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If more iterations are performed to improve decoding accuracy, then decoding performance improves, but decoding time increases and buffer congestion may occur

Engineering Contradiction:
Improvedecoding accuracyVSAvoiddecoding time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent employs feedback mechanisms where the iteration controller continuously monitors buffer space and available decoding time, then adjusts the iteration count accordingly. This closed-loop control ensures that decoding accuracy is optimized within the constraints of available time and buffer resources, preventing both excessive iterations and insufficient decoding.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs a sufficient number of iterations to achieve acceptable decoding accuracy rather than always maximizing iterations. By adjusting the iteration count to match actual needs based on monitored conditions, the system avoids unnecessary time consumption while maintaining reliable decoding performance.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If fewer iterations are used to reduce decoding time, then latency decreases, but decoding accuracy deteriorates and packet loss increases

Engineering Contradiction:
Improvedecoding throughputVSAvoiddecoding success rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the iteration count based on real-time conditions rather than using a fixed value. When buffer space and decoding time are abundant, more iterations are performed to ensure high decoding success rates. When resources are constrained, the iteration count is reduced to maintain throughput, achieving a dynamic balance between productivity and reliability.

Inventive Principle:
Principle #15Dynamics

4Productivity

If the same iteration number is allocated to all data packets, then resource allocation is simple, but efficiency is reduced for low-noise corrupted codewords that require fewer iterations

Engineering Contradiction:
Improvedecoding efficiencyVSAvoidresource allocation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies different iteration counts to different data packets based on their specific conditions (signal quality, buffer status, available time). This localized resource allocation allows low-noise corrupted codewords to use fewer iterations while high-noise packets receive more iterations, optimizing overall decoding efficiency without requiring complex per-packet analysis algorithms.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS10615822B1Systems and methods for dynamic iteration control in a low-density parity-check (LDPC) decoder
Publication Date: 2020.04.07 NXP USA INC
  • US10615822B1 patent drawing
  • US10615822B1 patent drawing
  • US10615822B1 patent drawing

AI summary

Systems and methods described herein provides a method for dynamically allocating an iteration number for a decoder. The method includes receiving, at an input buffer, an input signal including at least one data packet. The method further includes calculating a first iteration number for decoding the at least one data packet. The method further includes monitoring at least one of available space of the input buffer and available decoding time for the at least one data packet. The method further includes dynamically adjusting the first iteration number to a second iteration number based on the available space or the available decoding time to continue decoding the at least one data packet.