A brief review of cooperative spectrum sensing: Issues and challenges

Spectrum sensing is a key function in cognitive radio network (CRN) to avoid harmful interference with licensed users and identify the free spectrum to improve spectrum utilization. However, major challenge arises when detection of license users is failed due to various issues like multipath fading, shadowing, receiver uncertainty etc. Use of cooperative spectrum sensing(CSS) technique minimizes the impact of these issues and improved the detection performance by exploiting spatial diversity. In this paper, a brief survey of CSS is provided by discussing its various types, techniques, cooperation models, characteristics comparison, and some related earlier works with involved challenges. At the prior of this discussion, a brief history of CRN and spectrum sensing technology is also provided to refresh the knowledge in this field.