Improving Channel Resilience for Task-Oriented Semantic Communications: A Unified Information Bottleneck Approach
Shuai Lyu, Yao Sun, Linke Guo, Xiaoyong Yuan, Fang Fang, Lan Zhang, Xianbin Wang
TL;DR
The paper tackles the challenge of channel-level distortions in task-oriented semantic communications (TSC) by introducing a unified channel-resilience framework grounded in the information bottleneck (IB). It freezes the existing encoder/decoder and uses artificial noise to estimate per-feature robustness, deriving an upper-bound objective $L(\sigma)$ and a per-feature robustness mask $r_k$ that guides transmission decisions. The IB-based robustness estimation yields a soft mask that prioritizes semantically important, resilient feature units, demonstrated through a real-time subchannel allocation case study showing improved performance under dynamic channel conditions. This approach enhances radio-resource efficiency by enabling task-specific semantic inference to remain reliable despite instantaneous channel variations.
Abstract
Task-oriented semantic communications (TSC) enhance radio resource efficiency by transmitting task-relevant semantic information. However, current research often overlooks the inherent semantic distinctions among encoded features. Due to unavoidable channel variations from time and frequency-selective fading, semantically sensitive feature units could be more susceptible to erroneous inference if corrupted by dynamic channels. Therefore, this letter introduces a unified channel-resilient TSC framework via information bottleneck. This framework complements existing TSC approaches by controlling information flow to capture fine-grained feature-level semantic robustness. Experiments on a case study for real-time subchannel allocation validate the framework's effectiveness.
