The K-User Linear Deterministic Broadcast Channel with Receiver Memory

This paper considers a cache-aided linear deterministic broadcast channel where receivers have memories. A novel multi-rate coded multicasting is proposed, which utilizes different signal strength levels at the receivers contrary to the conventional coded multicasting. We derive the required transmission time for given memory size, and analyze the memory- transmission time tradeoff which characterizes the relationship between memory size and required transmission time satisfying all user requests. A lower bound on the memory-transmission time tradeoff is also derived using cut-set bound and optimality of the proposed scheme is evaluated by comparing the achievable tradeoff of the proposed scheme with the lower bound. It is shown that the proposed scheme achieves much less required transmission time than the conventional coded multicasting when the signal strength levels at the users are different.