Study on a new nonuniform frequency density multicarrier radar signal and its performances

In target searching stage of radar seeker in modern encounter, the transmitted signal is required to have characteristics of high resolution, low probability of intercept and high Doppler tolerance. In order to overcome the disadvantage of OFDM signal's low Doppler tolerance, a new type of multicarrier signal with nonuniform frequency density is proposed, whose subcarriers and amplitude weighting are derived from nonlinear frequency modulation signals. By theoretical analysis and numerical simulation methods, characteristics of spectrum and ambiguity-function of the signal are derived and computed, and be compared with those of typical OFDM signal. The results show the signal has advantages of higher Doppler tolerance, range-Doppler decoupling, faster out-of-band attenuation and lower sidelobe of autocorrelation function, as is suitable to search and detect high speed target.