COMPREHENSIVE REVIEW ON SPECTRUM SENSING TECHNIQUES IN COGNITIVE RADIO

In wireless communication, spectrum sensing (SS) is one of the important techniques to study about the radio environment. Spectrum sensing phenomenon is used to estimate the unutilized frequency band of whole radio spectrum. Utilization of available spectrum can be improved by enhancing the spectrum sensing techniques. The performance of available spectrum sensing techniques may degrade substantially in low signal to noise ratio, multipath fading & shadowing environments. This may lead to increase in probability of false alarms and decrease in probability of detection. This paper gives the categorization of different spectrum sensing techniques (SST) and it also explores the different methods used in spectrum sensing. Comparison of energy detector (ED), matched filter detection (MFD), cyclostationary feature detection (CFD), waveform detection (WD) and eigen value detection (EVD based on their methodology and accuracy is also present in this paper. Various issues associated with these spectrum sensing techniques are highlighted here and futuristic solutions proposed for improvement in existing spectrum sensing techniques.