Information rate analysis of ASK-based molecular communication systems with feedback

摘要

In this paper we develop lower and upper bounds on the capacity of an amplitude shift keying (ASK)-based molecular communication (MC) system with feedback. Analyzing the effect of feedback on theperformance of MC is motivated by the growing use of feedback in controlling drug delivery. Basedon causal knowledge of the number of transmitted and received molecules, the input probability ofsymbols is adapted so as to maximize directed information in the molecular communication channel.We considered one dimensional channel with drift velocity caused by blood flow. In our system,molecules propagate in a fluid with a drift velocity; the receiver absorbs the molecule unless it issaturated (saturation models a limit on ligand binding). The input is limited by a toxicity constraint ofinjected molecules. We also study the effects of feedback on the achievable information rates in termsof the time delay in receiving the feedback. We show that, especially for higher values of toxicityconstraint and sequence length, feedback, in terms of causal knowledge of the number of deliveredmolecules, improves performance of ASK-based molecular communication.