Dynamic Encoding Scheme for State Estimation Over Wireless Sensor Networks

Abstract

In this brief, we consider the privacy-preserving strategies of the distributed state estimator over wireless sensor networks. Aiming at an eavesdropper who can intercept the data transmitted on the communication channel and the feedback channel, we analyze two scenarios, i) one can randomly intercept the estimates and the ACK signals of a certain sensor; ii) one can intercept multiple channels of different sensors and their ACK signals. For the first scenario, we design a dynamic encoding scheme to encode the transmitted data by using the characteristics of the channel model and the history estimates. For the second scenario, we propose a two-step code to prevent the eavesdropper from using other channel packets to decipher the current channel packets. We use the gap between the values deciphered by the eavesdropper and decoded by the sensor as the privacy index to evaluate the degree of robust privacy protection. Finally, we provide some simulations to illustrate the effectiveness of the proposed encoding schemes.