A Modified 3EED Spectrum Sensing Algorithm Using an Adaptive Decision Threshold

Cognitive Radio (CR) systems require an efficient Spectrum Sensing (SS) technique to implement their opportunistic medium access. Energy Detection (ED) is one of the most used SS techniques. Recently, a modified ED algorithm was proposed, which investigates two additional neighboring sensing slots, besides the current one, i.e., three-Event Energy Detection 3EED. However, the previously proposed 3EED algorithm uses a fixed decision threshold, which is set for a target false-alarm probability. In this paper, we propose a novel Adaptive threshold 3EED (A3EED) algorithm that minimizes the decision error probability for given Signal-to-Noise Ratio (SNR) and Primary User (PU) signal's average duty cycle values. Comparing the decision performance of these algorithms, for low SNR values, we prove a decision SNR gain of more than 1 dB of A3EED over the Adaptive Classical ED (ACED).