Performance Enhancement Of Spectrum Sensing For Cognitive Radio Network Using Three-Stage Detection Technique Over Awgn Channel

Abstract

The Use Of Wireless Communication Resources, Namely Energy And Spectrum, Has Significantly Expanded Recently. Considering Its Scarcity And Improper, Spectrum Becomes An Even More Important And Severe Resource To Deal With. Radio Spectrum Is One Of The World?�?S Most Extremely Regulated And Restricted Natural Resources That Has Suffered Even More Limitation Due To A Rapid Increase In The Availability Of Wireless Device, Which Has Greatly Expanded Their Applications. According To Many Studies On Static Allocation, The Licensed Spectrum Bands Are Not Fully Utilizedheavily. In Order To Mitigate Incongruity Ideas Of Spectrum Scarcity And Spectrum Underutilization, The Cognitive Radio (CR) Technology Considered As An Optimistic Solution. In CR, Spectrum Sensing Is A Critical Step In Identifying The Spectrum Gaps Or Spectrum Holes. To Detect Whether Primary User Is Present Or Not, Many Spectrum Sensing Techniques Such As Energy Detection (ED), Entropy Detection, Matched Filter And Cyclostationary Feature Detection Have Been Developed. Among Those, Energy Detection (ED) Has Public The Most Observance From Researchers Due To Its Fast Sensing Time, Simplicity On Implementation And Low Computational Complexity. Nevertheless, Due To Noise Uncertainty Problem, The Performance Of Conventional Detector Is Very Low At Low Signal To Noise Ratio (SNR). In This Thesis, Three-Stage Spectrum Sensing Technique Is Proposed To Improve The Performance Of Single Stage And Two-Stage Spectrum Sensing Techniques And Also To Overcome The Problem Occurred Due To Uncertainty Of Noise At Low SNR Values. Furthermore, The Performance Comparison Among Three Stage, Two Stage And Single Stage Spectrum Sensing Techniques Are Performed Over Additive White Gaussian Noise (AWGN) Channel. The Proposed Three-Stage Detection Technique Has An About 1 Db And 2.5 Db Performance Improvement As Compared To Two-Stage ED+ Renyi Entropy (RE) And Two-Stage ED+ Kapurs Entropy (KE) Respectively. The Cooperative Three-Stage Detection Technique Using OR Rule Has An About 4 Db And 5 Db Performance Improvement As Compared To Single Node And AND Rule Cooperative Spectrum Sensing (CSS) Technique Respectively At NU=5. The Parameters Like Receiver Operating Characteristic (ROC) Curve, Complementary ROC (CROC) Curve And Probability Of Detection (Pd) At Various SNR Are Used To Estimate The Performance Of Spectrum Sensing Approach.