Temporal Design Tradeoffs in the Sensing of Cognitive Radio System

Cognitive radio (CR) is proposed as an approach to solve the conflict between the spectrum congestion and under-utilization. The practicality of CR system is promised by the avoidance of the interference to the primary systems. The performance of CR system includes the interference to the primary system and the utilization efficiency of the spectrum. In this paper, we define two indices to measure the two aspects of the performance of CR system. The situation of CR system working in both non-cooperative form and cooperative form are studied. Temporal tradeoffs should be made in the sensing of CR system. To determine the sensing time and the sensing frequency of CR system, the detection performance of the detectors applied in the system should be taken into consideration. Based on the two indices, we propose a design principle to make these tradeoffs.