LDPC Decoding with Staggered Iterations for Variable Channel Conditions

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Solution Overview

Problem

Current low-density parity-check (LDPC) decoding methods face limitations in decoding performance and iteration efficiency due to fixed computation and storage times, which do not adapt well to varying channel conditions, leading to suboptimal decoding rates in communication systems.

Innovation Solution

The proposed method employs multiple decoding units that perform storage and decoding computation in staggered time periods, allowing for adjustable iteration times based on channel conditions, with each unit capable of performing decoding computation across multiple periods to increase the number of iterations and improve decoding performance, while also enabling simultaneous operation without interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixed computation and storage times are used in LDPC decoding, then the decoding process is simple to implement, but the decoding performance and iteration efficiency are limited

Engineering Contradiction:
Improvedecoding performanceVSAvoiddecoding process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic time allocation for decoding computations by allowing different decoding units to operate for different durations based on channel conditions. The computation time is adjusted dynamically - some decoding units perform more iterations than others - to optimize decoding performance while adapting to varying communication channel qualities, thereby resolving the contradiction between simple implementation and high decoding performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of computation time duration across different decoding units. By varying the number of decoding iterations (a key parameter) for different decoding units based on channel conditions, the system achieves better decoding performance without requiring complete redesign of the decoding architecture, thus balancing performance improvement with implementation complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the number of decoding iterations is increased to improve decoding performance, then the decoding accuracy improves, but the decoding time and computational load increase

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

Solution Approach 1:

The patent applies local quality by allowing different decoding units to perform different numbers of iterations based on their specific channel conditions and error patterns. Instead of uniformly increasing iterations for all data, the system selectively applies more iterations only where needed (in units experiencing poorer channel conditions), thereby improving decoding accuracy while minimizing the overall time penalty.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts the number of iterations for each decoding unit based on real-time channel conditions. When channel conditions are good, fewer iterations are performed; when conditions deteriorate, more iterations are allocated. This dynamic adaptation resolves the contradiction by making iteration count flexible rather than fixed, optimizing both accuracy and time efficiency.

Inventive Principle:
Principle #15Dynamics

3Productivity

If multiple decoding units operate simultaneously to increase processing capacity, then the throughput increases, but interference between units may occur

Engineering Contradiction:
Improvedecoding throughputVSAvoiddecoding correctness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the decoding process into multiple independent decoding units that operate in parallel but with differentiated time allocations. Each unit is assigned a specific time window for computation, and the system coordinates their operations to prevent resource conflicts and interference. This segmentation allows high throughput while maintaining decoding correctness through proper isolation and coordination of parallel operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic action by organizing decoding units to operate in staggered time periods rather than all simultaneously. Different units are activated in different time windows, creating a periodic pattern of operation that increases overall throughput while preventing interference between units through temporal separation and coordinated scheduling.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS8756476B2Method and apparatus for decoding low-density parity-check codes
Publication Date: 2014.06.17 HUAWEI TECH CO LTD
  • US8756476B2 patent drawing
  • US8756476B2 patent drawing
  • US8756476B2 patent drawing

AI summary

A method and an apparatus for decoding low-density parity-check codes are provided. A first decoding unit performs decoding computation on a first code word from a second time period to an Oth time period. A second decoding unit performs decoding computation on a second code word from a third time period to an (O+1)th time period. An Nth decoding unit performs decoding computation on an Nth code word from an (N+1)th time period to an (N+O−1)th time period. An Mth decoding unit performs decoding computation on an Mth code word from an (M+1)th time period to an (M+O−1)th time period. Each decoding unit may perform decoding computation in multiple time periods.