Spectrum Sensing for Future Wireless Systems: From Theory to Throughput

Cognitive Radio (CR) is an emerging and fascinating technology to deal with the inevitable problem of spectrum scarcity and under-utilization. The idea of this system is to allow Unlicensed or Secondary Users (SU) to use the spectrum in times it is not used by the Licensed or Primary users (PU). Central to the CR cycle is the vital function of spectrum sensing, which intends to detect the unused spectrum. Whereas the spectrum reallocation intends to share the unused spectrum without introducing harmful interference to other users. Effective spectrum reallocation mainly relies on the good performance of spectrum sensing, and hence, spectrum sensing is considered one of the critical elements.