CRC-Concatenated Polar Encoding Without Dummy Bit Transmission
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Solution Overview
Problem
Current wireless communication technologies, such as LTE and NR, face challenges in achieving efficient error correction, particularly for smaller code block sizes, due to poor minimum distance in polar codes, leading to the transmission of dummy bits in CRC concatenated polar codes, which reduces efficiency and increases power consumption.
Innovation Solution
The use of odd-weighted CRC generator polynomials or discarding/scrambling the first code bit in CRC concatenated polar encoding to avoid transmission of dummy bits, thereby improving the minimum distance and efficiency of the encoding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If polar codes are used for error correction in wireless communication, then the spectral efficiency is improved and Shannon capacity is approached, but the minimum distance becomes poor for smaller code block sizes, leading to transmission of dummy bits
Solution Approach 1:
The patent combines CRC outer code with polar inner code to create a concatenated coding scheme. The CRC code provides excellent minimum distance properties while the polar code achieves capacity, and their combination resolves the contradiction by leveraging the strengths of both codes simultaneously.
Solution Approach 2:
The patent creates a composite coding structure where CRC and polar codes are layered together. This composite approach allows the system to achieve both good minimum distance (from CRC) and high spectral efficiency (from polar code), resolving the technical contradiction between these two parameters.
2Reliability
If CRC concatenated polar encoding is used to improve minimum distance, then error correction performance is enhanced, but dummy bits are transmitted which reduces encoding efficiency and increases power consumption
Solution Approach 1:
The patent extracts and removes the dummy bit from the encoded output. By identifying that the first bit is always zero and removing it before transmission, the system maintains the error correction benefits of CRC concatenated polar coding while eliminating the efficiency penalty and power consumption increase caused by transmitting unnecessary dummy bits.
Solution Approach 2:
The patent discards the dummy bit at the encoder side and recovers the original information at the decoder side through appropriate processing. This approach maintains reliability while improving productivity by not transmitting wasted bits.
3Device complexity
If dummy bits are transmitted in CRC concatenated polar codes, then the encoding structure is simplified, but power consumption increases and transmission efficiency decreases
Solution Approach 1:
The patent extracts the harmful dummy bit from the transmission stream. By removing this unnecessary component, the system reduces power consumption and improves transmission efficiency while maintaining the simplicity of the encoding structure through the use of standard CRC and polar code components.
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. 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.