Differential coding in networked controlled linear systems

This paper investigates the closed-loop properties of the differential coding scheme known as Delta-modulation (A-M) when used in feedback loops within the context of linear systems controlled through some communication network. We propose a new modified scheme of the original form of the Delta-M algorithm which improves the closed-loop properties. The new coding structure explicitly uses information from the system model. Stability properties for both: the continuous-time and the discrete-time version of this new algorithm are assessed. The results shows that the stability domain and the resulting precision of the Delta-M is limited by the position of the unstable poles of the system