Slepian-Wolf Code Partitioning for Flexible Multi-Source Rate Allocation

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Solution Overview

Problem

Existing Slepian-Wolf coding methods face challenges in practical implementation and rate allocation among encoders for distributed source coding, particularly in achieving arbitrary rate allocation while maintaining low encoding and decoding complexity.

Innovation Solution

The system employs channel code partitioning by generating sub-matrices from a generator matrix to create parity matrices for each correlated data source, allowing for flexible rate allocation and joint decoding with low complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If asymmetric codes are used to compress one source while using the other as side information, then lossless compression can be achieved at corner points of the Slepian-Wolf bound, but the system cannot flexibly allocate rates among encoders without time sharing which requires synchronization

Engineering Contradiction:
Improverate allocation flexibilityVSAvoidsynchronization complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention partitions a single channel code into multiple subcodes, where each subcode is assigned to a different encoder. This segmentation allows each encoder to operate independently with its own subcode, eliminating the need for time sharing and synchronization while enabling flexible rate allocation. The generator matrix is divided into sub-matrices, and parity matrices are generated for each subcode based on the corresponding sub-matrix.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple different codes are used to achieve arbitrary rate allocation among encoders, then rate flexibility is improved, but encoding and decoding complexity increases

Engineering Contradiction:
Improverate allocation flexibilityVSAvoidencoding and decoding complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention uses a single universal channel code that serves multiple functions by partitioning it into subcodes. Instead of employing multiple different codes, one code structure is designed to handle all rate allocation requirements through its subcode partitions. This universal approach maintains low complexity while achieving arbitrary rate allocation, as the same decoding algorithm can be applied to all subcodes.

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

3Device complexity

If a single code is used for joint decoding of multiple sources, then decoding complexity is reduced, but the ability to achieve arbitrary rate allocation among encoders is limited

Engineering Contradiction:
Improvedecoding complexityVSAvoidrate allocation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The single channel code is segmented into multiple subcodes through partitioning the generator matrix. Each subcode maintains the structure of the original code, allowing the use of the same low-complexity decoding algorithm. The segmentation enables arbitrary rate allocation because different numbers of subcode bits can be transmitted by different encoders, while the joint decoder processes all received bits using the unified code structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS7779326B2Multi-source data encoding, transmission and decoding using Slepian-Wolf codes based on channel code partitioning
Publication Date: 2010.08.17 TEXAS A&M UNIVERSITY
  • US7779326B2 patent drawing
  • US7779326B2 patent drawing
  • US7779326B2 patent drawing

AI summary

System and method for designing Slepian-Wolf codes by channel code partitioning. A generator matrix is partitioned to generate a plurality of sub-matrices corresponding respectively to a plurality of correlated data sources. The partitioning is performed in accordance with a rate allocation among the plurality of correlated data sources. A corresponding plurality of parity matrices are generated based respectively on the sub-matrices, where each parity matrix is useable to encode data from a respective one of the correlated data sources.