Polarization orthogonality for the co-existence of wideband fading cognitive networks

Orthogonality techniques for cognitive radio networks are important since they enable the primary and secondary terminals to efficiently share the spectral resources in the same location simultaneously. In this paper, we investigate a simple, yet powerful, orthogonality scheme by exploiting the polarimetric dimension. More precisely, we evaluate a scenario where the cognitive terminals use cross-polarized communications in a communication channel subject to wideband (or narrowband) Rayleigh fading. A primary exclusive region in which cognitive terminals are not allowed to transmit is defined and its radius is computed. Finally, the overall performance of the proposed solution is evaluated in terms of network throughput.