Waveform and energy based dual stage sensing technique for cognitive radio using RTL-SDR

The prevailing condition of forthcoming cognitive radio networks will be the existence of primary user and other unknown secondary users in a same band of interest. Thus to accommodate such situation, a combined spectrum sensing scheme is proposed which utilizes waveform detector(WD) and energy detector(ED) based on the available signal pattern of Primary User(PU) waveform. By not activating the second stage, when the PU waveform is known, the proposed detector shortens the sensing time when compared to the conventional two-stage detector. Here the combined dual stage detector performance is analyzed by capturing the real time signal using an Realtek (RTL2832U) Software Defined Radio(SDR) known as RTL-SDR and experimented on MatLab platform to decide the availability of vacant spectrum band. In this paper we analyze the combined detector performance and verified their influence on received signal to noise ratio and sample size.