Narrow-Band Waveform Design in Cooperative Spectrum Sensing

In order to use the idle spectrum effectively and improve the spectrum efficiency, cognitive radio technology has attracted extensive attention. On account of low detection probability and low spectrum efficiency of previous spectrum sensing framework, a relay-based cooperative spectrum sensing framework is proposed and multiple narrow-band waveforms are required for different users which could be separated easily in the fractional Fourier transform domain. Aiming at this problem, this paper proposes a narrow-band waveform design method, and considering the energy concentration property of chirp signals in fractional Fourier transform domain, we adopt chirp signal as basic function to design narrow-band waveforms and CVX toolbox is used to solve the problem. Simulation results show that the de-signed two waveforms can be separated effectively and hence the detection probability of the cognitive framework could be increased. Moreover, the designed waveforms have relatively high power efficiency so that the transmission performance of cognitive users can be improved as well.