  Semantic communication is deemed as a revolution of Shannon's paradigm in the
six-generation (6G) wireless networks. It aims at transmitting the extracted
information rather than the original data, which receivers will try to recover.
Intuitively, the larger extracted information, the longer latency of semantic
communication will be. Besides, larger extracted information will result in
more accurate reconstructed information, thereby causing a higher utility of
the semantic communication system. Shorter latency and higher utility are
desirable objectives for the system, so there will be a trade-off between
utility and latency. This paper proposes a joint optimization algorithm for
total latency and utility. Moreover, security is essential for the semantic
communication system. We incorporate the secrecy rate, a physical-layer
security method, into the optimization problem. The secrecy rate is the
communication rate at which no information is disclosed to an eavesdropper.
Experimental results demonstrate that the proposed algorithm obtains the best
joint optimization performance compared to the baselines.
