Group orthogonal arrays for elimination of multiple-time-around echos in radars (USH0000548)
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2008-Apr-28
US Statutory Invention Registration (SIRs)
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Sets of group-complementary code arrays which have the property of being ually orthogonal over a subinterval of their total cross-correlation function have been identified. These group-orthogonal arrays are generated by a multiplication operation upon a given group-complementary array using a matrix which has diagonal elements from vectors which are orthogonal. Composite code arrays are synthesized by interleaving rows from the group-orthogonal set of arrays, and applying the resulting rows of codes to bi-phase modulate pulses in bursts. The resulting composite waveform has the desirable property of temporal (zero-Doppler) sidelobe cancellation in the maximum unambiguous range interval and response cancellation over one or more multiple-time-around range intervals of an equivalent uncoded pulse sequence. The waveforms also have the property of maximizing the receiver response in one of the multiple-time-around range intervals, while achieving response cancellation in the maximum unambiguous range interval of an equivalent uncoded pulse sequence.