Real time hardware implementable spectrum sensor for Cognitive Radio applications

A fundamental problem for Cognitive Radios (CR) is spectrum sensing, secondary users need to reliably detect weak primary signals of possibly different types over a targeted wide frequency band in order to identify spectral holes for opportunistic communications. In this paper energy detection technique based on Neyman-Pearson criterion is implemented to detect the presence of deterministic primary user (PU) signals in the channel. We designed a hardware implementable energy detector on a wireless testbed software defined radio (SDR) using USRP2 and an experimental study is carried out to measure the required SNR to achieve the desired probability of detection and false alarm. A comparative study was also made between the SNRs obtained from frequency and time domain analysis.