Symbol-wise Puncturing for HARQ Integration with Probabilistic Amplitude Shaping

TL;DR

This paper introduces a symbol-wise puncturing method for HARQ with probabilistic amplitude shaping, maintaining shaping gain and reducing distribution distortion across retransmissions, outperforming traditional sequential puncturing.

Contribution

It proposes a novel symbol-wise puncturing scheme that preserves probabilistic amplitude shaping gains in HARQ systems, addressing limitations of sequential puncturing.

Findings

Achieves at least 0.6 dB shaping gain over uniform case.

Reduces distribution distortion, gaining over 1.2 dB at BLER 10^-3.

Outperforms sequential puncturing in retransmissions.

Abstract

In this letter, we propose a symbol-wise puncturing scheme to support hybrid automatic repeat request (HARQ) integrated probabilistic amplitude shaping (PAS). To prevent the probability distribution distortion caused by the traditional sequential puncturing and realize the promised gain of PAS, we perform symbol-wise puncturing on the label sequence of the shaped modulation symbols. Our simulation results indicate that the proposed puncturing scheme achieves a stable shaping gain across the signal-to-noise ratio of at least 0.6 dB compared with the uniform case under the same throughput, while the gain of sequential puncturing drops rapidly with retransmissions. Moreover, in each transmission, the proposed scheme is able to reduce the distribution distortion that achieves over 1.2 dB gain at a block error rate (BLER) of ${10^{-3}}$. In contrast, for sequential puncturing, the distribution is severely distorted and the BLER performance is even worse than that of the uniform case in retransmissions.