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 meanings, 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）无线网络发展的关键技术。然而，在实践中提供有效的语义表示颇具挑战。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，源消息可在不损失其预期含义的前提下，被表征在低维子空间中，从而显著提升通信效率。本文首先阐述了语义知识库的基本原理，并通过构建三个子知识库（即源知识库、任务知识库与信道知识库）提出了一种生成式语义通信架构。随后，详细描述了各子知识库的构建方法，并探讨了它们在语义编码与传输中的应用。本文还通过案例研究展示了生成式语义通信相较于传统语法通信及经典语义通信的优越性。总而言之，本文为生成式语义通信这一令人兴奋的未开拓领域奠定了科学基础。