Current studies on semantic communications mainly focus on efficiently extracting semantic information to reduce bandwidth usage between a transmitter and a user. Although significant process has been made in the semantic communications, a fundamental design problem is that the semantic information is extracted based on certain criteria at the transmitter side along, without considering the user's actual requirements. As a result, critical information that is of primary concern to the user may be lost. In such cases, the semantic transmission becomes meaningless to the user, as all received information is irrelevant to the user's interests. To solve this problem, this paper presents a user centric semantic communication system, where the user sends its request for the desired semantic information to the transmitter at the start of each transmission. Then, the transmitter extracts the required semantic information accordingly. A key challenge is how the transmitter can understand the user's requests for semantic information and extract the required semantic information in a reasonable and robust manner. We solve this challenge by designing a well-structured framework and leveraging off-the-shelf products, such as GPT-4, along with several specialized tools for detection and estimation. Evaluation results demonstrate the feasibility and effectiveness of the proposed user centric semantic communication system.

翻译：当前关于语义通信的研究主要集中于高效提取语义信息以减少发射端与用户间的带宽占用。尽管语义通信已取得显著进展，但其根本设计问题在于语义信息仅依据发射端的特定标准进行提取，而未考虑用户的真实需求。这可能导致用户关注的关键信息丢失。在此情况下，语义传输对用户失去意义，因为接收到的所有信息均与用户兴趣无关。为解决该问题，本文提出一种以用户为中心的语义通信系统，用户在每次传输开始时向发射端发送所需语义信息的请求，发射端据此提取相应的语义信息。关键挑战在于发射端如何理解用户的语义信息请求，并以合理且稳健的方式提取所需信息。我们通过设计结构化的框架，并利用现有成熟工具（如GPT-4）及若干专用检测与估计工具来解决这一挑战。评估结果验证了所提出的以用户为中心的语义通信系统的可行性与有效性。