Leveling and Sectoring based Localization of Primary User for preventing Interference in Cognitive Radio Network

Abstract

radio is viewed as a novel approach for improving the utilization of a precious natural resource: the radio electromagnetic spectrum. The whole framework of CR is generally a mapping from spectrum sensing to spectrum utilization. In cognitive networks, a cognitive user can interfere with the primary user, cognitive user must be aware of the presence of primary user. If primary user is passive listening, it is not possible to identify the presence of this passive listening user through spectrum sensing. When a user is passive listening, it does not acknowledge or respond to any request. In this situation, hidden node problem arises in cognitive networks. In another situation two cognitive user transmitting to each other makes passive listening primary user wait to communicate though it can communicate easily without any interruption here exposed node problem arise. Cooperative sensing can identify the presence of primary user multiple cognitive user cooperate to reach an optimal global solution. Sharing the information among each other will reduce time and will increase detection efficiency. Localization technique can be done where GPS is not available. Localization of primary users can be done by leveling and sectoring approach. Each CU identified by two coordinate level id and sector id. Base station calculates the relative position of PU based on signal strength. For cooperative sensing here is used centralized cooperative spectrum sensing with relay-assisted schema where sensing channel and report channel can complement and cooperate with each other to improve the performance of cooperative sensing. Count for wrongly enabled CUs is 0 for all the scenarios, which shows that the interference (hidden node problem) to the primary users is prevented. Lastly error percentage is evaluated in MATLAB for the five scenarios such as leveling localization, sectoring localization, varying PU, varying CU, and varying network area in forms of grid size for performance evaluation and hence the desired value will be generated.