Cooperative spectrum sensing for cognitive radio with multiple secondary users

Spectrum sensing is a key component in cognitive radio networks, where secondary users are able to use the frequency bands when they sense that no primary users are using those bands. In this paper, we investigate an energy detector scheme used to deal with the issues related to spectrum sensing and interference avoidance for multinode cognitive radio networks. Then, an extensive analysis on cooperative diversity, which uses randomized space time codes (RSTC) over asynchronous dispersive channels, is discussed. Numerical results are provided in order to demonstrate the effectiveness of the proposed energy detector and randomization schemes.