Transport Block Decoding With Soft-Bit-Based Iteration Allocation

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Solution Overview

Problem

In communication systems, decoding transport blocks segmented into code blocks is inefficient due to a fixed number of iterations being assigned to each code block, leading to either excessive iterations for easier blocks or insufficient iterations for more difficult ones, especially with high-order modulations like QAM16 and QAM64, where soft-bit reliability varies significantly.

Innovation Solution

The method involves studying the soft-bit mixtures of code blocks to allocate a variable number of iterations based on the relative reliability of soft-bits, using look-up tables or direct measurement of average soft-bit values to optimize decoder scheduling, allowing for more efficient decoding by adjusting the number of iterations for each code block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed number of iterations is assigned to each code block, then the decoding process is simple to implement, but decoding efficiency deteriorates because easier code blocks receive unnecessary iterations while difficult ones receive insufficient iterations

Engineering Contradiction:
Improvedecoding efficiencyVSAvoiddecoder scheduling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic iteration allocation by introducing a buffer that temporarily stores decoded code blocks and tracks unused iterations. The iteration count for each code block is adjusted dynamically based on real-time buffer status and soft-bit reliability metrics, transforming the static fixed-iteration approach into a flexible adaptive system that optimizes decoding efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of iteration count from a fixed value to a variable that depends on soft-bit reliability measurements. By measuring the average soft-bit value and comparing it against thresholds, the system adjusts the iteration parameter adaptively, allocating more iterations to code blocks with lower reliability and fewer iterations to those with higher reliability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If more iterations are assigned to ensure all code blocks are decoded, then decoding reliability improves, but bandwidth utilization deteriorates due to increased processing time

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidbandwidth utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by treating different code blocks differently based on their individual soft-bit reliability characteristics. Instead of uniformly applying the same iteration count to all code blocks, the system measures each code block's soft-bit average and assigns iterations locally according to its specific needs, ensuring reliable decoding only where necessary

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by allocating iterations selectively rather than applying maximum iterations to all code blocks. Code blocks with high soft-bit reliability receive fewer (partial) iterations, while only those with low reliability receive full or excessive iterations, optimizing the trade-off between reliability and processing speed

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the number of iterations is increased for difficult code blocks, then decoding accuracy improves, but power consumption increases

Engineering Contradiction:
Improvedecoding accuracyVSAvoiddecoder power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent changes the iteration parameter based on measured soft-bit reliability, adjusting the decoding accuracy level dynamically. By measuring the soft-bit average and comparing it to thresholds, the system modifies the iteration count parameter to achieve sufficient decoding accuracy while minimizing unnecessary processing for easily decoded code blocks

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a dynamic power-management approach where the decoder adapts its processing intensity based on real-time channel conditions and code block characteristics. The buffer mechanism and soft-bit measurement enable the system to dynamically adjust iteration counts, reducing power consumption for code blocks that require minimal processing while maintaining accuracy for difficult ones

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2579468B1Method and device for decoding a transport block of a communication signal
Publication Date: 2020.05.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2579468B1 patent drawingFigure 1~2
  • EP2579468B1 patent drawingFigure 3~4
  • EP2579468B1 patent drawingFigure 5~6

AI summary

The present invention relates to a device and method of decoding code blocks of a transport block of a communication signal using a decoder. The method comprises making an assumption about how many decoder iterations should be used for different code blocks of the code blocks of the transport block, wherein the assumption is made based on a study of code block soft-bits. The method also comprises decoding the transport block using different numbers of decoder iterations for the different code blocks, based on the made assumption about how many decoder iterations should be used for the different code blocks.