Optimal OFDM waveform design for extended targets detection

In this paper, the problem of extended targets detection in signal-dependent interference based on orthogonal frequency division multiplexing (OFDM) waveform is addressed. Compared with other radar waveforms, OFDM has a thumbtack ambiguity function and the spectrum can be elaborately designed through changing the complex weights transmitted over different subcarriers. First, the optimal waveform design algorithm based on maximizing the signal-to-noise ratio (SNR) of the output receiver is introduced and the analytic expression of the waveform with optimal energy spectral density (ESD) is also derived. Then, combining the characteristic of OFDM waveform, a cycle iterative algorithm (CIA) based on fast Fourier transform (FFT) is proposed to search for the optimal solution of the objective function. Numerical examples show the ESD of designed waveform matches the optimal ESD well and the detection performance is also improved by optimizing the frequency weights of transmitted waveform.