A spectrum sensing system based on sub-Nyquist rate sampling

In this paper, the proposed architecture uses modulated wideband converter for sub-Nyquist rate sampling. It samples with more than one branch by low rate ADCs, and then the compressive sensing recovery algorithm recovers support which is implied where the probable active band is. Although the modulated wideband converter needs more hardware components, its rate is far below the Nyquist rate. It implies that is cheaper than the Nyquist rate components, and it is easy to implement. However, the reconstructive procedure is computationally complex in conventional modulated wideband converter, because it interpolates the reconstructive signal to Nyquist rate. In order to reduce computational complexity, the signal is not reconstruct completely. Nevertheless, the main purpose of the proposed architecture is to do spectrum sensing, the low rate signal is included the narrow band information. Since the original point in frequency domain is the summation of sequence in time domain, the fast Fourier transform processor is replaced by summation procedure. The spectrum sensing system can reduce computational loads by 93.3% compared to adaptive multitaper spectral detector with Nyquist rate sampling.