Spectral Efficiency-Aware Codebook Design for Task-Oriented Semantic Communications

Fuente: arXiv
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Autores principales: Zhang, Anbang, Guo, Shuaishuai, Feng, Chenyuan, Liu, Shuai, Du, Hongyang, Min, Geyong
Formato: Preprint
Publicado: 2025
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author Zhang, Anbang
Guo, Shuaishuai
Feng, Chenyuan
Liu, Shuai
Du, Hongyang
Min, Geyong
author_facet Zhang, Anbang
Guo, Shuaishuai
Feng, Chenyuan
Liu, Shuai
Du, Hongyang
Min, Geyong
contents Digital task-oriented semantic communication (ToSC) aims to transmit only task-relevant information, significantly reducing communication overhead. Existing ToSC methods typically rely on learned codebooks to encode semantic features and map them to constellation symbols. However, these codebooks are often sparsely activated, resulting in low spectral efficiency and underutilization of channel capacity. This highlights a key challenge: how to design a codebook that not only supports task-specific inference but also approaches the theoretical limits of channel capacity. To address this challenge, we construct a spectral efficiency-aware codebook design framework that explicitly incorporates the codebook activation probability into the optimization process. Beyond maximizing task performance, we introduce the Wasserstein (WS) distance as a regularization metric to minimize the gap between the learned activation distribution and the optimal channel input distribution. Furthermore, we reinterpret WS theory from a generative perspective to align with the semantic nature of ToSC. Combining the above two aspects, we propose a WS-based adaptive hybrid distribution scheme, termed WS-DC, which learns compact, task-driven and channel-aware latent representations. Experimental results demonstrate that WS-DC not only outperforms existing approaches in inference accuracy but also significantly improves codebook efficiency, offering a promising direction toward capacity-approaching semantic communication systems.
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id arxiv_https___arxiv_org_abs_2508_04223
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Spectral Efficiency-Aware Codebook Design for Task-Oriented Semantic Communications
Zhang, Anbang
Guo, Shuaishuai
Feng, Chenyuan
Liu, Shuai
Du, Hongyang
Min, Geyong
Signal Processing
Image and Video Processing
Digital task-oriented semantic communication (ToSC) aims to transmit only task-relevant information, significantly reducing communication overhead. Existing ToSC methods typically rely on learned codebooks to encode semantic features and map them to constellation symbols. However, these codebooks are often sparsely activated, resulting in low spectral efficiency and underutilization of channel capacity. This highlights a key challenge: how to design a codebook that not only supports task-specific inference but also approaches the theoretical limits of channel capacity. To address this challenge, we construct a spectral efficiency-aware codebook design framework that explicitly incorporates the codebook activation probability into the optimization process. Beyond maximizing task performance, we introduce the Wasserstein (WS) distance as a regularization metric to minimize the gap between the learned activation distribution and the optimal channel input distribution. Furthermore, we reinterpret WS theory from a generative perspective to align with the semantic nature of ToSC. Combining the above two aspects, we propose a WS-based adaptive hybrid distribution scheme, termed WS-DC, which learns compact, task-driven and channel-aware latent representations. Experimental results demonstrate that WS-DC not only outperforms existing approaches in inference accuracy but also significantly improves codebook efficiency, offering a promising direction toward capacity-approaching semantic communication systems.
title Spectral Efficiency-Aware Codebook Design for Task-Oriented Semantic Communications
topic Signal Processing
Image and Video Processing
url https://arxiv.org/abs/2508.04223