Real-Time Implementation of Spectrum Sensing Techniques in Cognitive Radios

摘要

Wireless communication requirements of higher sampling frequencies and bandwidth are ever increasing. For this purpose, exploitation of underutilized spectrum bands was one the challenging research targets. Cognitive Radio (CR) is a promising solution to overcome the "limited bandwidth" issue. Software defined radio (SDR) is the enabler of CR. The aim of the thesis is to adopt the vacant TV channels for secondary users. Spectrum sensing prototype has been proposed to detect TV white space (TVWS). The prototype has been developed using Universal Software Radio Peripheral (USRP) and examined to sense TVWS in the real time world. The conducting analysis of obtained measurements showed the state of unoccupied spectrum bands in the UHF band ranges from 500 MHz to 698 MHz in the urban area of Windsor, Ontario, Canada. Two different spectrum sensing techniques namely, the energy detector, and pilot-tone detector were employed to get the result with minimum computational complexity. Experiments show that the presence of incumbent users can be easily detected using the spectrum sensing techniques mentioned in the thesis. The experimental results have demonstrated the validity of the proposed prototype.