CRC-Aided Polar Coding for Lower-Complexity BP Decoding
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Solution Overview
Problem
Current polar coding techniques for wireless communications, such as those used in 5G NR networks, face challenges in achieving efficient encoding and decoding due to high decoding complexity, especially for medium to large block-lengths, which limits their adoption for high-throughput regimes.
Innovation Solution
The proposed solution involves implementing CRC-aided polar encoding and decoding methods, specifically using cyclic redundancy check (CRC) dependent relaxation operations in polar encoding and periodic CRC-aided Belief Propagation (BP) decoding to reduce complexity and improve error correction performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polar coding techniques are used for wireless communications, then the encoding and decoding can be implemented, but the decoding complexity is high especially for medium to large block-lengths
Solution Approach 1:
The patent segments the polar code decoding process into multiple stages using CRC-aided list decoding. The decoder divides the codeword into multiple candidate lists, processes them separately with CRC checks at intermediate stages, and merges results progressively. This segmentation reduces the computational burden at any single stage compared to conventional exhaustive decoding methods.
Solution Approach 2:
The patent applies preliminary CRC checks during the encoding process to pre-identify and mark positions that will require special handling during decoding. By performing preliminary error detection and marking critical positions before the actual decoding operation, the system prepares the data structure to facilitate lower-complexity decoding operations later.
2Productivity
If conventional polar coding techniques are used, then encoding can be performed, but the latency is high which limits adoption for high-throughput regimes
Solution Approach 1:
The patent implements periodic CRC checking at multiple stages of the decoding process rather than a single final check. This periodic verification allows the decoder to identify and correct errors earlier in the process, preventing error propagation and reducing the need for re-decoding operations, thereby lowering overall latency.
Solution Approach 2:
The patent introduces CRC bits as intermediary elements that mediate between the encoded data and the decoding process. These CRC bits act as a bridge that provides rapid error detection capability, allowing the system to quickly determine whether full decoding is necessary or if errors can be handled more efficiently, thus reducing average latency.
3Reliability
If standard polar encoding is used with CRC, then error detection capability is provided, but the encoding complexity increases due to additional CRC operations
Solution Approach 1:
The patent merges the CRC encoding operations with the polar encoding process by integrating the CRC calculation into the existing encoding pipeline. Rather than performing CRC encoding as a completely separate sequential operation, the system combines both functions to share computational resources and reduce overall encoding complexity.
Solution Approach 2:
The patent designs the encoding structure to serve multiple functions simultaneously: the same encoding operations provide both polar code generation and CRC calculation capabilities. This multi-functionality reduces the need for separate dedicated hardware or software modules for each function, thereby reducing overall system complexity.
Data Source
AI summary
Methods and apparatuses for polar coding, including cyclic redundancy check (CRC) aided encoding and belief propagation (BP) decoding for polar codes in wireless communications, are provided. For example, a method comprises determining: 1) a first set of encoding nodes used for creating CRC bits, 2) a first set of polarization branches, each associated with a respective encoding node of the first set of encoding nodes, and 3) a second set of polarization branches, each of the second set of polarization branches is at least one level higher than a respective polarization branch of the first set of polarization branches. The method also comprises performing polar encoding operation(s) for the second set of polarization branches, generating a second set of encoding nodes based on the performed polar encoding operation(s) for the second set of polarization branches, and transmitting polar code bits using the generated second set of encoding nodes.