LTE Communications and Networks

6Spectrum Sensing Mechanisms in Cognitive Radio Based LTE Femtocells

Tazeen S. Syed and Ghazanfar Ali Safdar

School of Computer Science and Technology, University of Bedfordshire, Luton, UK

The ever‐increasing demand for wireless technology has rendered the spectrum a restricted resource. Most research work has shown that efficient usage of spectrum can be accomplished by employing the emerging cognitive radio (CR) technology. The secondary users (SUs) utilize the spectrum when it is unoccupied and vacate it when the primary users (PUs) return. Sensing the spectrum holes is the most vital process of the CRs. When it comes to cellular communication indoors, the coverage is substantially poor. To overcome this issue, Long‐Term Evolution (LTE) femtocells are employed, the main drawback being, however, cross‐ and co‐tier interference. This issue could be resolved by integrating LTE femtocells with CR technology innovations. The LTE cognitive femtocells have CR capabilities of sensing the spectrum and preventing interference by proper allocation of the spectrum. This chapter provides an insight into fundamental signal processing used for spectrum sensing and explores the conventional spectrum sensing techniques used in CR networks. We then investigate different models and statistics used for performance analysis of these schemes and present the state‐of‐the‐art research results, which outline the widely used models and statistics for specific sensing techniques. Further, a comparison ...