Joint spectrum sensing and transmission using a sector antenna in cognitive radio network

This paper presents joint sensing and transmission using a sector antenna in cognitive radio network. A ray tracer technique is used for this study which deterministically models a typical urban multipath environment. Joint sensing and transmission is performed using three, six, and nine sector antennas. Three different scenarios are studied, where for each scenario five locations are selected for joint sensing and transmission. At each location directional sensing identifies the directions which offer spatial opportunity for a cognitive node. Directional transmission is then performed with power control only in those directions which offer opportunity. As a result of secondary transmission, two parameters, namely service probability and range of communication are calculated in each scenario using different number of sectors. The results show that both service probability and range of communication increase with increase in number of sectors, but saturation is achieved and, again decreases when nine sectors are reached, indicating that six sector antenna is the optimum choice for exploiting the spatial resource in cognitive radio in a typical urban multipath environment.