  This paper presents optimization issues of energy detection (ED) thresholds
in cooperative spectrum sensing (CSS) with regard to general Gaussian noise.
Enhanced ED thresholds are proposed to overcome sensitivity of multiple noise
uncertainty. Two-steps decision pattern and convex samples thresholds have been
put forward under Gaussian noise uncertainty. Through deriving the probability
of detection (Pd) and the probability of false alarm (Pf ) for independent and
identical distribution (i.i.d.) SUs, we obtain lower total error rate (Qe) with
proposed ED thresholds at low signal-to-noise-ratio (SNR) condition.
Furthermore, simulation results show that proposed schemes outperform most
other noise uncertainty plans.
