Spectrum Sensing & Signal Identification Using RTL-SDR

Abstract

Cognitive radio is one of the modern techniques in the field of wireless communication in order to solve the spectrum scarcity problem. Spectrum scarcity occurs due to the rapid increase of the applications in wireless communication which results in the problem of bandwidth. Hence in order to solve this problem cognitive radio follows the cognitive cycle in which spectrum sensing acts as a major procedure. Spectrum sensing largely focus on the effective and efficient utilization of the spectrum. The spectrum allocation plays an important role in this. There are two type users primary user (PU) and secondary user (SU).Primary user those who are legally allotted to use the spectrum but for secondary user without license to use the spectrum avoiding interference can be done by spectrum sensing. In this key factor is to find the spectrum holes then allocate those to the secondary user. For this purpose energy detection and cyclostationary detection two procedure , are followed here, to determine spectrum holes. Here the analysis to find the white spaces are doneby collecting the real time signal with RTL-SDR and experimented on the platforms like matlab, Simulink, GNU radio and spectrum analyzer. Finally the comparison between the methods are stated with a complementary ROC plot. Finally P25 analysis is also done for C4FM, CQPSK which are phases of project 25. This idea is to improve the efficiency of the spectrum utilization.