Cooperative Spectrum Sensing in OFDM Based on MIMO Cognitive Radio Sensor Networks

Sharing of frequency spectrum between licensed primary users and unlicensed secondary users (SUs) requires reliable detection of spectrum occupancy by the SUs. We present a a new cooperative spectrum sensing in OFDM system based on MIMO cognitive radio (CR) sensor networks. We present a new interference temperature estimation approach based on OFDM technique in MIMO system. Frequency spectrum sensing combination of the observed energy values from different cognitive radio users is investigated. Square-law-combining (SLC) is theoretically proved to be nearly optimal in low signal-to-noise ratio (SNR) region, an usual scenario in the context of MIMO cognitive radio sensor networks. Simulation and experiment results show a substantial improvement for the utilizations of frequency spectrum of SUs.