ACM International Symposium on Theory, Algorithmic Foundations, and Protocol Design for Mobile Networks and Mobile Computing (MobiHoc)
Quantum-Inspired Semantic Communication Capacity Analysis based on von Neumann Entropy
Zhu Han, Dusit Tao Niyato
Abstract
Semantic communication aims to transmit the task-relevant uncertainty that remains after common knowledge has been taken into account. However, the semantic communication capacity and rate distortion analysis have not been well investigated theoretically. Inspired by quantum entanglement across a black-hole horizon, this paper develops a quantum-inspired framework, where we present a von Neumann entropy bridge between new information and existing common knowledge. Conditioned on the existing common knowledge and the new information, we show that the corresponding von Neumann entropy is continuous and nondecreasing. To give this von Neumann entropy a practical interpretation, we define an auxiliary classical spectral-mode source, whose conditional probabilities are the eigenvalues of the reduced state. Then the resulting semantic capacity and tradeoff are discussed between the fully new information (the Shannon capacity case) and fully common knowledge (no new information) limits. Furthermore, we derive a conditional rate-distortion function, a source-channel feasibility condition, and a task-specific semantic-sample throughput over a cost-constrained discrete memoryless channel. A binary example illustrates the effects of common knowledge, semantic distinguishability, distortion tolerance, and the physical channel capacity.