Resilient Recursive State Estimation for Nonlinear Systems with Decode-and-Forward Relays

This paper is concerned with the resilient recursive state estimation problem for a class of nonlinear time-varying systems. To improve the signal quality, a decode-forward (DF) relay is placed in the system operation, which is used to compensate for the remote transmission capability of the sensors by introducing coding decoding rules. Additionally, considering the effect of random perturbations on the estimator parameters, a resilient state estimation (RSE) scheme is proposed. A recursive state estimator is designed such that an upper bound (UB) is ensured on the estimation error covariance (EEC) in the presence of the DF relay and estimator gain (EG) perturbations. Then, by solving the corresponding difference equations, the EG matrix is accurately designed which minimizes the derived UB. Finally, the feasibility of the designed RSE algorithm is guaranteed by a simulation example.