Vector Quantizer Configuration for Noisy Channel Distortion Control

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Solution Overview

Problem

Existing methods for optimizing vector quantizers for noisy channels are inefficient as they treat the design and analysis of optimal noisy channel quantization separately, leading to sensitivity to channel conditions and lack of structural information about the optimal VQ, and fail to jointly design VQs with channel conditions.

Innovation Solution

A method for configuring a quantizer that iteratively updates quantization codewords and space partitioning based on average symbol error probability, using a quantizer optimization module to select and update codewords and partitions until a threshold is met, to minimize end-to-end distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If vector quantizers are designed using conventional centroid condition and nearest neighbor condition separately from channel conditions, then the design process is simpler, but the performance is very sensitive to variation of channel conditions and lacks structural information about optimal noisy channel VQ

Engineering Contradiction:
Improvedesign process complexityVSAvoidperformance sensitivity to channel conditions
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines the vector quantizer design with channel condition considerations into a unified framework. The optimal noisy channel VQ is derived by merging the source coding objective (minimizing distortion) with the channel characteristics (transition probabilities), creating a joint design that simultaneously optimizes both aspects rather than treating them separately.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces new design parameters that incorporate channel transition probabilities into the quantizer design process. By changing the optimization parameters to include channel statistics, the system adapts the VQ structure to specific channel conditions, reducing performance sensitivity while maintaining design tractability.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If iterative algorithms based on separate design conditions are used, then implementation is straightforward, but performance is very sensitive to variation of channel conditions

Engineering Contradiction:
Improveimplementation easeVSAvoidperformance stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent performs preliminary incorporation of channel statistics into the quantizer design before actual transmission occurs. By pre-adapting the VQ to channel conditions using available channel statistics, the system prepares an optimized configuration that remains robust against channel variations, reducing the need for complex real-time adaptations.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If random index assignment is used with VQ optimized without channel conditions, then analysis is simplified, but the analysis does not shed light on how to design optimal noisy channel VQs jointly with channel conditions

Engineering Contradiction:
Improveanalysis complexityVSAvoidjoint design information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent introduces feedback of channel statistics into the quantizer design process. By using channel transition probabilities as feedback information to guide the VQ optimization, the system creates a closed-loop design approach where channel conditions continuously inform the quantizer structure, enabling joint optimization without excessive analytical complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2243251B1Method and system for optimizing quantization for noisy channels
Publication Date: 2015.04.08 BLACKBERRY LTD
  • EP2243251B1 patent drawingFigure 1
  • EP2243251B1 patent drawingFigure 2
  • EP2243251B1 patent drawingFigure 3

AI summary

ABSTRACT Methods are described for configuring a quantizer to achieve improved end-to-end distortion performance when transmitting encoded source data over a noisy channel. The codebook and partitioning are selected using an iterative process of determining an updated codebook and an updated partition space, where the updated codebook is based, in part, on the average symbol error probability of the channel. Complete knowledge of the transitional probabilities of the channel is not required. Variants of the iterative process are described.