An Efficient Composite Two-Tier Threshold Cooperative Spectrum Sensing Technique for 5G Systems

There are fixed thresholds in the conventional double threshold sensing techniques. There is no sensing or confusion region when the test statistic lies between high and low thresholds leading to meager detection probability and lengthier sensing time for the upcoming fifth-generation networks. Hence, there occur problems of low SNR and threshold discrepancies in conventional detectors. So, a novel composite two-tier threshold (CTTT) cooperative spectrum sensing algorithm has been proposed that utilizes the confusion region, and the energy vectors, RSSI vectors, and distance vectors are exploited by the secondary users in a two-tier process to sense the spectrum. Relay centers (RCs) are introduced that can combine the decisions of the secondary users according to different decision strategies and decide about final spectrum availability. The proposed model operates at 2.4 GHz in the sub-6 GHz band of fifth-generation communication. The proposed scheme's performance is assessed on false alarm rate, detection probability, miss detection rate, sensing time, and bit error rate vs. SNR graphs with the conventional methods. The simulated results depict that the proposed scheme outperforms the existing techniques with sensing time as low as 1.09 s, a very low miss detection probability of 0.0002100, and a significantly less BER of 0.0001, giving robust spectrum predictions for the 5G environments.