Cooperative Spectrum Sensing in Cognitive Radio under Noise Uncertainty

Cooperative energy spectrum sensing has been proved effective to detect the spectrum holes in Cognitive Radio (CR). However, its performance may suffer from the noise uncertainty, which is portrayed by the SNR wall in some literatures. In this paper we analyze the spectrum sensing performance under noise uncertainty and propose a new approach to obtain the SNR wall. In addition, a suboptimal liner cooperative sensing algorithm with wavelet denoising is proposed to reduce the impact of noise uncertainty. Analysis and numerical results show that cooperative sensing and wavelet denoising can significantly improve the sensing performance under noise uncertainty condition.