Radio frequency spread spectrum for distributed control systems

Abstract

The application of spread spectrum techniques in recent years to communications, navigation and test equipment has produced significant results which are not possible with standard techniques. In this thesis, direct sequence radio frequency spread spectrum (RF/SS) is used for communication between Remote field Terminal Units (RTUs) and host computer in Distributed Control System (DCS) applications. This new system is basd on differential phase shift keying modulation and code-divisionmultiple-access. It also uses a new polling access protocol between the host computer and the RTUs. Overall system is simulated, using a SLAM II software package, for different data rates and various bit-error probabilities under two separate cases: 1) Data acquisition and 2) Data acquisition and control. Network simulation indicates the feasibility of the proposed access protocol and provides the system designer with variety of options to select the network parameters basd on his requirements. The proposed system is expected to yield substantial improvement in the operation of present DCS sysems