Priority-Based Polarized Transmission for Feedback Channels in Cooperative Spectrum Sensing Systems

In this letter, we present a priority-based polarized transmission scheme for enhancing the performance of cooperative spectrum sensing (CSS) systems, by reducing transmission errors over the feedback channel. In our scheme, the polarization principle is applied and different types of CSS information are transmitted with different priorities. More specifically, the spectrum sensing results corresponding to the occupied sub-bands have higher priority over those related to idle/underused sub-bands. The higher priority bits are then transmitted over the near-noiseless bit-channels that approach the maximal capacity, while the less important bits are transmitted over the noisy bit-channels. Simulations are performed over additive white Gaussian noise and Rayleigh fading channels, with either AND or OR rule employed at the fusion center. The results demonstrate that compared with existing schemes, the proposed scheme can achieve better reliability, flexibility, and sensing performance.