Resource Allocation in A Dual-Sensor Update System for Age of Information Minimization

This work focuses on the resource allocation in a remote monitoring system where two sensors use the zero-wait strategy to sample the same physical processes and transmit updates to the monitor. To improve the timeliness of updates, a resource allocation optimization problem is formulated to minimize the average age of information (AoI) of the system. An algorithm that seeks for the optimum is proposed. For the high signal-to-noise ratio (SNR) regime, an approximate closed-form expression for the optimal power allocation is given. In the low SNR regime, we show that the average AoI is minimized when all the power is allocated to the sensor with a large bandwidth. Moreover, we generalize the obtained results to bandwidth allocation optimization. Furthermore, the resource allocation problem is considered in a non-orthogonal multiple access case and the optimal rate pair is presented.