Ultra Wideband Spectrum Sensing for Cognitive Electronic Warfare Applications

In this paper, the design of ultra wideband (UWB) fast Fourier transform (FFT) for electronic warfare applications such as cognitive electronic warfare, low probability of intercept radar detection and spectrum sensing in communication and radar bands is presented. In recent electronic warfare receivers, by the development of high capacity analog to digital converters (ADC), instantaneous bandwidth of the processed signals is increased rapidly. In order to detect and extract the parameters of the received signals, firstly spectrum sensing ability using an ultra wide band FFT should be accomplished. In the proposed forms of UWB FFT design, smaller size of FFT structures are combined via reordering of phase shifted samples of parallel received data. Using proposed design, high throughput data samples of ADC can be digitally processed with low FPGA clock rates. The design of combined FFT structure is implemented on FPGA board that has 2.5 gigasample per second (GSPS) ADC with 16 parallel data channels. The whole picture of the spectrum acquired by combined FFT structure for multi-signal environment that includes 4 different frequency carrier signals is presented.