GII-Polar Codes for Block Fading Channels

2026-07-04

AI Summary

This work addresses the high decoding latency of polar codes under successive cancellation (SC/SCL) decoding in block-fading channels by proposing a generalized set-interleaved (GII) polar code construction. The approach virtually couples two length-$N$ polar codewords within a low-dimensional nested codebook to enable parallel decoding, while leveraging the joint error-correction capability between the interleaving layer and the nested codes to enhance performance. Evaluated over block Rayleigh fading channels, the proposed scheme significantly reduces decoding latency while achieving bit error rate performance comparable to or better than that of a single polar code of length $2N$, thereby offering an effective trade-off between decoding efficiency and reliability.

Abstract

Polar codes are proven to be capacity-achieving codes, being gradually practiced in wireless communications. However, their successive cancellation (SC) and successive cancellation list (SCL) decoding incur latency challenge especially for long codes. This paper proposes the generalized integrated interleaved (GII)-polar codes for block Rayleigh fading channels, yielding both reduced decoding latency and competent decoding performance. Under the GII paradigm, two consecutive polar codewords of length $N$ are virtually coupled through a nested codebook which has a lower dimension, capable of correcting more errors. The component polar codes are known as interleaves of a GII-polar code. If decoding of an interleave fails, it can be projected into the decoding of the nested one, enabling richer error patterns to be corrected by each interleave. Since decoding of the interleaves can be performed in parallel, GII-polar codes yield a reduced decoding latency over a single polar code of length $2N$. Our simulation results validate both the decoding latency and performance merits of the proposed coding scheme under block Rayleigh fading channel.

Problem

• Polar codes
• decoding latency
• block fading channels
• successive cancellation decoding
• Rayleigh fading

Innovation

• GII-polar codes
• block fading channels
• parallel decoding
• nested codebook
• decoding latency reduction