Demonstration of real-time spectrum sensing for cognitive radio

Spectrum sensing detects the availability of the radio frequency spectrum in a real-time fashion, which is essential and vital to cognitive radio. The requirement for real-time processing indeed poses challenges on implementing spectrum sensing algorithms. Trade-off between the complexity and the effectiveness of spectrum sensing algorithms should be taken into consideration. In this paper, a fast Fourier transform (FFT) based spectrum sensing algorithm called FAR is introduced. It is the beauty of the algorithm that the decision variable is insensitive to noise level. Parameter selection for the algorithm is considered as well, toward minimizing computational complexity. A small form factor (SFF) software denned radio (SDR) development platform (DP) is employed to implement a spectrum sensing receiver with FAR algorithm. Performance of FAR algorithm is evaluated on the SFF SDR DP, and real-time spectrum sensing is demonstrated. FAR algorithm is friendly to hardware implementation and it is effective to detect signals at low SNR.