Cooperative Spectrum Sensing Improvement Based on Fuzzy Logic System

To attenuate the channel fading effects, a spectrum sensing policy for coordinating a cooperative sensing is proposed by adding a Hopping Sequence (HS) module to the detectors based on a fuzzy logic system (FLS). A significant effect on the spectrum efficiency is the ability of a secondary user (SU) to utilize a frequency slot for transmission in an idle channel. Hence, the SU needs to sense the related spectrum in order to classify a licensed frequency band as occupied or vacant. To implement the HS module, two hopping methods are proposed- Random Hopping (RA-H) and Sequential Hopping (SE-H). An enhancement in detection probability over conventional cooperative sensing has been achieved.