A sub-Nyquist sampling spectrum sensing system based on PXI bus for multiband signals

In this paper, a sub-Nyquist sampling system for multiband signals is presented, which can perform accurate spectrum sensing and reconstruction. The system is based on PXI bus and virtual instrument technology, which make the proposed system able to be adjusted flexibly for different input signals. Compressive sensing (CS) theory and modulated wideband converter (MWC) are adopted in the system. The detailed design process of the system is given in the paper. The extension method of observation matrix and the reconstruction algorithms are also explained in this paper. Experimental results show that the proposed system can sample the multiband signal at an extreme low frequency and recover the signal spectrum effectively.