Constant-Weight Signal Coding with Conjugate Dissections

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Solution Overview

Problem

Existing methods for encoding and decoding constant weight codes are inefficient, particularly for large values of weight w, resulting in processing times on the order of w^2, which can be problematic in applications where speed is crucial.

Innovation Solution

A new coding method that pre-codes input signals into a w-dimensional polytope with specific constraints, applies a nonlinear approximation of a linear transformation, followed by a second linear transformation to achieve a constant weight binary codeword, reducing processing time to approximately w·log w.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If piecewise linear algorithm P is used to map w-dimensional information vectors into code vectors, then encoding and decoding can be performed with a systematic method, but processing time increases to the order of w^2

Engineering Contradiction:
Improveencoding methodVSAvoidprocessing time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent segments the encoding process into distinct stages: mapping w-dimensional information vectors to code vectors using algorithm P, constructing binary code vectors of weight w, and reversing the operation for decoding. This segmentation allows each stage to be optimized independently, reducing overall processing time from O(w^2) to O(w·log w) while maintaining systematic encoding.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary mapping of w-dimensional information vectors into code vectors using algorithm P before constructing the final binary code vectors. This preliminary action organizes the data in a structured format that facilitates faster subsequent processing and reduces the computational complexity of the encoding operation.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If constant weight codes are used to communicate maximum symbols, then information capacity is maximized, but processing complexity increases for large weight values

Engineering Contradiction:
Improveinformation capacityVSAvoidprocessing complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent changes the parameter representation by mapping w-dimensional information vectors into code vectors with specific weight constraints. This parameter transformation allows the system to maintain maximum information capacity while reducing processing complexity through the use of structured code vectors that can be manipulated more efficiently.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transforms the problem from direct manipulation of constant weight codes to working with w-dimensional information vectors that are mapped to code vectors. This dimensional transformation allows for more efficient processing by operating in the w-dimensional space before mapping to the final constant weight representation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS7791511B1Constant weight coding of signals based on conjugate dissections
Publication Date: 2010.09.07 AT&T INTELLECTUAL PROPERTY II LP
  • US7791511B1 patent drawing
  • US7791511B1 patent drawing
  • US7791511B1 patent drawing

AI summary

A method for encoding and decoding codes of constant weight that is based on conjugate dissections, which progressively modifies element values of an input vector to satisfy the constraint that each encoded symbol is to comprise integer component elements even when the encoded symbol is generated through processing that involved permuting.