Nested Symmetric Polar Codes

2024-10-31

ICC 2025 - IEEE International Conference on Communications

AI Summary

To address the dynamic rate/length adaptation and ultra-reliable low-latency decoding requirements in URLLC and mMTC scenarios, this paper proposes a rate- and length-flexible, fully nested symmetric polar code. We first establish the theoretical foundation for nested symmetric polar codes, enabling fully nested and rate-compatible sequence construction. By integrating data-driven design, channel polarization analysis under symmetry constraints, and automated automorphism group modeling, we jointly optimize the AED-SC decoding architecture. The proposed code supports adaptive rate and length switching, significantly enhancing short-block reliability: under AED decoding, it outperforms state-of-the-art schemes and even surpasses the 5G standard CRC-aided SCL decoder. This demonstrates the critical role of nested symmetric structure in achieving high-reliability short-code decoding.

Technology Category

• Search and Optimization: Learning to Search
• Machine Learning: Deep Generative Models & Autoencoders
• Cognitive Modeling & Cognitive Systems: Neural Spike Coding

Application Category

• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

In this paper, we propose a data-driven algorithm to design rate- and length-flexible polar codes. While the algorithm is very general, a particularly appealing use case is the design of codes for automorphism ensemble decoding (AED), a promising decoding algorithm for ultra-reliable low-latency communications (URLLC) and massive machine-type communications (mMTC) applications. To this end, theoretic results on nesting of symmetric polar codes are derived, which give hope in finding a fully nested, rate-compatible sequence suitable for AED. Using the proposed algorithms, such a flexible polar code design for automorphism ensemble successive cancellation (SC) decoding is constructed, outperforming existing code designs for AED and also the 5G polar code under cyclic redundancy check (CRC)aided successive cancellation list (SCL) decoding.

Problem

• Designing rate- and length-flexible polar codes
• Developing codes for automorphism ensemble decoding applications
• Creating nested symmetric polar codes for reliable communications

Innovation

• Data-driven algorithm designs flexible polar codes
• Nested symmetric codes enable automorphism ensemble decoding
• Flexible design outperforms 5G polar code performance