A tree-structured DFT filter bank based spectrum sensor for estimation of radio channel edge frequencies in military wideband receivers

Accurate Spectrum sensing is a vital task in military wideband receivers. The discrete Fourier transform filter bank (DFTFB) used in conventional energy detectors fails to detect the exact locations and edges of occupied frequency bands (channels). In this paper, an energy detector based on tree-structured DFTFB (TDFTFB) is proposed for detecting the edges of channels. Simulation results are presented to show the trade-off between accurate edge detection and the number of filter bank stages required. Simulation results show that the proposed method detects the edges of channels with an error less than 2% using a 2-stage, 8 point TDFTFB while the conventional DFTFBs cannot detect the edges of the channels. The receiver operating characteristics (ROC) plot for the proposed method shows better performance than the conventional DFTFBs.