CRC-Concatenated Polar Encoding Without Dummy Bit Transmission
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Solution Overview
Problem
Current wireless communication technologies, such as LTE and 5G, face challenges in achieving efficient error correction, particularly for smaller code block sizes, where polar codes suffer from poor minimum distance, leading to inefficiencies in data transmission due to the inclusion of dummy bits in CRC concatenated polar codes.
Innovation Solution
The implementation of CRC concatenated polar encoding techniques that avoid transmitting dummy bits by using odd-weighted CRC generator polynomials, discarding the first code bit, or performing bit-level scrambling, thereby improving the minimum distance and transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CRC concatenated polar codes are used for error correction, then reliability is improved, but dummy bits are included in the transmission which reduces productivity
Solution Approach 1:
The patent extracts and removes the dummy bit from the CRC concatenated polar code structure. Specifically, when using even-weighted CRC generator polynomials, the first code bit of the polar-encoded CRC sequence is always zero and carries no information. The invention removes this dummy bit from transmission, thereby improving transmission efficiency while maintaining the error correction capability provided by the CRC outer code and polar inner code.
2Ease of manufacture
If even-weighted CRC generator polynomials are used, then encoding simplicity is improved, but dummy bits are generated which increases loss of information
Solution Approach 1:
The patent applies the extraction principle by removing the dummy bit that is inevitably generated when using even-weighted CRC generator polynomials. The first bit of the polar-encoded CRC sequence is identified as always being zero and is extracted from the transmission stream, preventing the loss of transmission resources on dummy data while maintaining the encoding simplicity of even-weighted polynomials.
Solution Approach 2:
The patent changes the parameter of the CRC generator polynomial from even-weighted to odd-weighted. By using odd-weighted polynomials (where the sum of coefficients is odd), the first code bit of the polar-encoded sequence is no longer guaranteed to be zero, thereby eliminating the dummy bit generation while maintaining comparable encoding complexity.
Data Source
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. 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. In another method, only odd-weighted generator polynomials are selected.