Low-complexity algorithms for spatio-temporal directional spectrum sensing with applications in cognitive radio

摘要

A suit of low complexity signal processing algorithms are identified for the directional spectrum sensing and two-dimensional (2-D) spatio-temporal white space detection in cognitive radio systems. The concept of spectral white spaces in 2-D spatio-temporal frequency space is reviewed based on the specific spectral properties of 2-D spatio-temporal array signals. The proposed system contains an array processing stage, magnitude-fast-Fourier-transform (FFT) stage followed by an energy detection stage. The use of 2-D infinite impulse response (IIR) filters having beam-shaped passbands in the 2-D frequency space is identified as a low complexity solution for the array processing stage for the directional enhancement of radio signals. A low complexity algorithm that delivers the magnitude FFT is described for the 16-point case and computational complexity is expressed in closed-form.