CRC-Concatenated Polar Encoding Without Dummy Bit Transmission

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G and LTE, face challenges in achieving efficient error correction due to the poor minimum distance of polar codes at lower code block sizes, leading to the transmission of dummy bits which reduce encoding efficiency and increase power consumption.

Innovation Solution

The implementation of CRC concatenated polar encoding techniques that use odd-weighted CRC generator polynomials or discard/discard and scramble even-weighted CRC bits to avoid transmitting dummy bits, thereby enhancing the minimum distance and encoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If even-weighted CRC generator polynomials are used for CRC concatenated polar encoding, then the encoding process is simplified, but dummy bits are transmitted which reduce encoding efficiency and increase power consumption

Engineering Contradiction:
Improveencoding process simplicityVSAvoidencoding efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the parameter of CRC generator polynomial selection from even-weighted to odd-weighted polynomials. This parameter change eliminates the generation of dummy bits while maintaining the simplicity of the encoding process, thereby resolving the contradiction between encoding simplicity and encoding efficiency.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If even-weighted CRC generator polynomials are used for CRC concatenated polar encoding, then the encoding process is simplified, but power consumption increases due to transmission of dummy bits

Engineering Contradiction:
Improveencoding process simplicityVSAvoidpower consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameter of CRC generator polynomial selection from even-weighted to odd-weighted polynomials. This parameter change eliminates the generation of dummy bits, thereby reducing power consumption while maintaining the simplicity of the encoding process.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If polar codes are used for error correction, then the encoding scheme is simplified, but the minimum distance is poor at lower code block sizes

Engineering Contradiction:
Improveencoding scheme complexityVSAvoidminimum distance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent merges CRC outer code with polar inner code to form a concatenated coding scheme. This combination leverages the simplicity of polar codes and the excellent minimum distance properties of CRC codes, thereby resolving the contradiction between encoding scheme simplicity and minimum distance performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a composite coding structure by combining CRC and polar codes. This composite approach integrates the strengths of both coding schemes, achieving both simplicity and excellent error correction performance through the synergistic combination of outer CRC code and inner polar code.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3707843B1Methods and apparatus for CRC concatenated polar encoding
Publication Date: 2024.10.30 QUALCOMM INC
  • EP3707843B1 patent drawingFigure 1
  • EP3707843B1 patent drawingFigure 2
  • EP3707843B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure generally relate to techniques for encoding and decoding bits of information using cyclic redundancy check (CRC) concatenated polar encoding and decoding. The CRC concatenated polar encoding techniques may avoid transmission of dummy bits. A method generally includes obtaining the bits of information to be transmitted. The method includes performing CRC outer encoding of the bits of information using an even-weighted generator polynomial to produce CRC encoded bits. The method includes performing polar inner encoding of the CRC encoded bits to generate a codeword. The method includes discarding a first code bit at a beginning of the codeword. The shortened codeword is transmitted over a wireless medium. In another method, bit-level scrambling is performed on the CRC encoded bits before the polar encoding to avoid generating a dummy bit. In another method, only odd-weighted generator polynomials are selected to avoid generating the dummy bit.