### A Constant Factor Approximation Algorithm for Event-Based Sampling

- R. Cogill, S. Lall and J. Hespanha.
- Proceedings of the American Control Conference, p. 305--311, 2007.

We consider a control system in which sensor data is transmitted from the plant to a receiver over a communication channel, and the receiver uses the data to estimate the state of the plant. Using a feedback policy to choose when to transmit data, the goal is to schedule transmissions to balance a trade-off between communication rate and estimation error. Computing an optimal policy for this problem is generally computationally intensive. Here we provide a simple algorithm for computing a suboptimal policy for scheduling state transmissions which incurs a cost within a factor of six of the optimal achievable cost.