Orthogonal frequency division multiplexing in distributed radar apertures

In previous work, frequency diversity has been shown to be an effective means of exploiting distributed radar apertures. Frequency diversity allows for each transmission to be isolated and processed independently of other frequencies. This paper presents an efficient implementation of a frequency diverse distributed radars, based on orthogonal frequency division multiplexing (OFDM), a concept borrowed from wireless communications. OFDM allows for frequency diversity to be implemented using only a single modulator/demodulator with the transformation, using a fast Fourier transform (FFT) to move between time and frequency domains as required. The resulting system is significantly simpler, but, as we will show, OFDM places a stringent constraint on the allowed sampling rate.