Cognitive node selection and assignment algorithms for weighted cooperative sensing in radar systems

Given the favourable transmission characteristics of the radio spectrum allocated for radar and the possibility for its temporal and spatial reuse, opportunistic access is very desirable. This opportunistic access can be implemented in a secondary cognitive communication system, which must have an accurate and reliable sensing capability in order to ensure safe and efficient operation. In this paper, the swept radar’s rotation mechanism is exploited to allow spectrum re-use; cooperative sensing is implemented in the secondary system in order to ensure accuracy. Several node teaming algorithms are proposed for cooperative sensing, along with the use of weighted sensing algorithms. The function of these teaming algorithms is to select the member nodes of the teams and to assign sensing task assignments within the team. Performance results show that selection of appropriate sensing nodes to join the sensing-active team for each sensing cycle and exploring their frequency diversity (to perform the sensing task at the most suitable frequency sub-channels), yields a substantial improvement in performance. In addition, it is shown that proper node teaming algorithms should be chosen based on several key factors, including the characteristics of the primary signal and the sensing team node’s computational capabilities.