Prior Knowledge Base

This chapter introduces the proposed framework for semantic communications, which includes semantic representations, semantic encoding and decoding, and semantic information transmission with the next-generation multiple access (NGMA), as shown in Fig. 3.1. Specifically, rules, methods, models, and training libraries are deployed at the cloud server and maintained at the edge server to provide prior semantic knowledge for the transmitter and receiver. Based on the semantic knowledge base, the transmitter performs semantic representation and semantic encoding of the multimodal source. The abstracted semantic information from multiple users is then transmitted using multiple access techniques. The information can be transmitted using traditional methods such as bit sequences or the semantic transmission system to effectively transmit semantic features. At the receiver, with the aid of the semantic knowledge base, a generative approach is adopted to achieve semantic fidelity in reconstructing high-resolution, stable, and smooth video data.