Beyond 1$\to$N Decoding: Capacity-Aware Rateless Polar Codes for IR-HARQ
This work provides a practical solution for next-generation wireless data channels by improving the flexibility and efficiency of polar codes for IR-HARQ systems.
This paper proposes a new framework for polar codes in IR-HARQ systems that generalizes the decoding order to prioritize reliable subblocks, enabling continuous and arbitrary transmission lengths. The proposed rateless codes achieve coding gains equivalent to independently optimized fixed-rate codes across all rates and lengths.
This paper introduces a novel framework for polar codes, designed for flexible Incremental Redundancy Hybrid Automatic Repeat Request (IR-HARQ). By generalizing the decoding order beyond the standard 1$\to$N sequence, we enable a capacity-aware scheduling strategy that prioritizes the decoding of reliable subblocks. The framework integrates nested parity-check polar construction and reverse bit-mapping to support continuous and arbitrary transmission lengths $E \in [N_{\min}, N_{\max}]$. Simulation results show that the proposed rateless codes match the coding gain of independently optimized fixed-rate codes across the entire range of rates and lengths. With a validated hardware implementation, this work provides a practical solution for next-generation wireless data channels.