Modified Reed Muller Coding for Pilot-Free Noncoherent Decoding

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Solution Overview

Problem

Current wireless communication technologies face challenges in achieving optimal decoding performance at low signal-to-noise ratios, particularly in noncoherent communication scenarios where Reed Muller codes result in high block error rates due to ambiguity caused by unknown phases in the communication channel.

Innovation Solution

The use of modified Reed Muller codes, where a row vector of all 1-values is removed from the Reed Muller generating matrix or a fixed-value bit is prepended to the information bit vector, allowing for encoding without pilot signals, thereby reducing decoding block error rates and improving performance in noncoherent communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If Reed Muller codes are used in noncoherent wireless communication, then the communication can be performed without pilot signals, but the decoding performance deteriorates due to high block error rates caused by phase ambiguity

Engineering Contradiction:
Improvecomplexity of transmission signalingVSAvoiddecoding performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts and removes the problematic all-1 row vector from the Reed Muller generating matrix. This extraction eliminates the source of phase ambiguity that causes high block error rates, while preserving the essential error-correcting capabilities of the code structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent modifies the generating matrix parameters by removing specific row vectors (all-1 rows) from the Reed Muller code structure. This parameter change transforms the code into a modified Reed Muller code that is suitable for noncoherent communication by eliminating phase ambiguity while maintaining coding efficiency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If modified Reed Muller codes are used to eliminate phase ambiguity, then block error rates are reduced, but the code structure complexity increases due to matrix modification

Engineering Contradiction:
Improveblock error rateVSAvoidcode structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The modification process extracts only the necessary all-1 row vectors from the original Reed Muller generating matrix. This selective extraction reduces the modified code structure complexity compared to complete code redesign, while still achieving the goal of eliminating phase ambiguity and reducing block error rates.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If Reed Muller codes are used without modification, then encoding is simple, but phase ambiguity causes high decoding block error rates in noncoherent scenarios

Engineering Contradiction:
Improveencoding simplicityVSAvoiddecoding block error rate
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent removes only the specific all-1 row vectors that cause phase ambiguity, preserving the majority of the simple Reed Muller code structure. This selective extraction maintains encoding simplicity while eliminating the decoding reliability problem in noncoherent communication.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The generating matrix parameters are minimally changed by removing only the problematic all-1 rows. This conservative parameter modification preserves the inherent simplicity of Reed Muller encoding while fixing the phase ambiguity issue that causes high block error rates.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4078865B1Noncoherent wireless communication using modified reed muller codes
Publication Date: 2025.01.15 QUALCOMM INC
  • EP4078865B1 patent drawingFigure 1
  • EP4078865B1 patent drawingFigure 2
  • EP4078865B1 patent drawingFigure 3A~3B

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may generate a Reed Muller generating matrix for an information bit vector that includes a plurality of information bits. The wireless communication device may remove, from the Reed Muller generating matrix, a row vector consisting of all 1-values to form a modified Reed Muller generating matrix. The wireless communication device may encode the information bit vector using the modified Reed Muller generating matrix to form a codeword. The wireless communication device may transmit the codeword without transmitting a pilot signal or demodulation reference signal for the codeword. Numerous other aspects are provided.