QPP Turbo Interleaver Sizing for Contention-Free Decoding

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Solution Overview

Problem

Existing turbo coding systems face challenges in implementing contention-free interleavers for various information block sizes, which affects decoding performance and memory access efficiency.

Innovation Solution

A method for selecting interleaver sizes using a set of predefined sizes, such as K' = α p< × f, where α is an integer, and adjusting sizes to avoid multiples of (2 m< -1, to ensure contention-free interleaving and efficient decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traditional turbo interleavers are used for various information block sizes, then decoding performance may be maintained, but memory access contentions occur that reduce decoding speed and parallelism efficiency

Engineering Contradiction:
Improvedecoding speedVSAvoidcontention-free property
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent changes the parameter of interleaver size to specific predefined values (K' = α^p × f) that guarantee contention-free properties. By constraining the interleaver size to follow this mathematical formula with α≥2, p≥1, and f≥1, the system ensures that memory access patterns remain contention-free while still supporting various information block sizes through appropriate selection of parameters.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If interleaver size is increased to support larger information blocks, then coding capacity improves, but memory access contentions increase reducing parallelism

Engineering Contradiction:
Improvesupport for various block sizesVSAvoidmemory access contention
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the interleaver size parameter into a structured form K' = α^p × f, where each component (α, p, f) can be independently selected. This segmentation allows the system to support various information block sizes by adjusting the parameters while maintaining the contention-free property, as the segmented structure ensures proper alignment with memory bank boundaries.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If non-contention-free interleavers are used, then implementation flexibility increases, but decoding performance degrades due to memory access conflicts

Engineering Contradiction:
Improveimplementation flexibilityVSAvoiddecoding performance
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent creates a universal interleaver size formula K' = α^p × f that serves multiple functions: it supports various information block sizes, guarantees contention-free memory access patterns, and enables high-speed parallel decoding. This single universal structure replaces the need for different interleaver designs for different block sizes, providing both flexibility and performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2102989B1Turbo-encoding with contention-free QPP interleavers
Publication Date: 2012.04.11 MOTOROLA MOBILITY LLC
  • EP2102989B1 patent drawingFigure 1~5
  • EP2102989B1 patent drawingFigure 2
  • EP2102989B1 patent drawingFigure 3~6

AI summary

Methods and apparatus for turbo encoding are provided herein. During operation of the turbo encoder (101) the size of the turbo interleaver (201) is determined in dependence on the information block size and the appropriate interleaving parameters are selected. These parameters configure the turbo interleaver, which is a contention-free interleaver and which is based on either a quadratic permutation polynomial QPP interleaver or an almost regular permutation ARP interleaver. If the information block size does not match a supported interleaver size, then the information block is padded by means of filler bits insertion.