International Journal of Engineering and Advanced Research Technology (IJEART)
The functionality of cognitive radio is to detect the presence and absence of licensed user (i.e.) primary user, in the spectrum so that the secondary user can use it. Many works has been contributed on spectrum sensing of cognitive radio with single user, which has less complexity but offers inferior detection performance compared to cognitive radio with multiple users. Further there arises hidden user problem in single user system which degrades the system performance. Therefore, it is advisable to use multiple cognitive radio users to sense the spectrum individually and combine their result at the fusion center. This technique is known as co-operative spectrum sensing.