Range sidelobe suppression in a desired Doppler interval
We present a novel method of constructing a Doppler resilient pulse train of Golay complementary waveforms, for which the range sidelobes of the pulse train ambiguity function vanish inside a desired Doppler interval. This is accomplished by coordinating the transmission of a Golay pair of phase coded waveforms in time according to the 1's and -1's in a biphase sequence. The magnitude of the range sidelobes of the pulse train ambiguity function is shown to be proportional to the magnitude spectrum of the biphase sequence. Range sidelobes inside a desired Doppler interval are suppressed by selecting a sequence whose spectrum has a high-order null at a Doppler frequency inside the desired interval. We show that the spectrum of the biphase sequence obtained by oversampling the length-2M Prouhet-Thue-Morse (PTM) sequence by a factor m has an Mth-order null at all rational Doppler shifts Θ0 = 2πl /m, where l ≠ 0 and m≠ 1 are co-prime integers. This spectrum also has an (M - 1)th-order null at zero Doppler and (M - h - 1)th-order nulls at all Doppler shifts Θ0 = 2πl /(2hm), where l ≠ 0 andm ≠ 1 are again co-prime and 1 ≤ h ≤ M - 1. ©2009 IEEE.
