Rate Distortion Approach to Joint Communication and Sensing With Markov States: Open Loop Case

Abstract: We investigate a joint communication and sensing (JCAS) framework in which a transmitter concurrently transmits information to a receiver and estimates a state of interest based on noisy observations. The state is assumed to evolve according to a known dynamical model. Past state estimates may then be used to inform current state estimates. We show that Bayesian filtering constitutes the optimal sensing strategy. We analyze JCAS performance under an open loop encoding strategy with results presented in terms of the tradeoff between asymptotic communication rate and expected per-block distortion of the state. We illustrate the general result by specializing the analysis to a beam-pointing model with mobile state tracking. Our results shed light on the relative performance of two beam control strategies, beam-switching and multi-beam.