Semantic communication is widely touted as a key technology for propelling the sixth-generation (6G) wireless networks. However, providing effective semantic representation is quite challenging in practice. To address this issue, this article takes a crack at exploiting semantic knowledge base (KB) to usher in a new era of generative semantic communication. Via semantic KB, source messages can be characterized in low-dimensional subspaces without compromising their desired meaning, thus significantly enhancing the communication efficiency. The fundamental principle of semantic KB is first introduced, and a generative semantic communication architecture is developed by presenting three sub-KBs, namely source, task, and channel KBs. Then, the detailed construction approaches for each sub-KB are described, followed by their utilization in terms of semantic coding and transmission. A case study is also provided to showcase the superiority of generative semantic communication over conventional syntactic communication and classical semantic communication. In a nutshell, this article establishes a scientific foundation for the exciting uncharted frontier of generative semantic communication.

翻译：语义通信被广泛认为是推动第六代（6G）无线网络的关键技术。然而，在实际中提供有效的语义表示颇具挑战性。为解决这一问题，本文尝试利用语义知识库（KB）开创生成式语义通信的新纪元。通过语义知识库，源消息可在低维子空间中被表征，同时不损害其期望含义，从而显著提升通信效率。首先介绍语义知识库的基本原理，并通过提出三个子知识库（即源知识库、任务知识库和信道知识库）来开发生成式语义通信架构。随后，描述各子知识库的详细构建方法，并阐述其在语义编码与传输中的应用。通过案例研究，展示了生成式语义通信相较传统句法通信及经典语义通信的优越性。总之，本文为生成式语义通信这一激动人心的未知前沿奠定了科学基础。