Removal of Range Ambiguities with Orthogonal Block Coding Techniques

This paper considers radar signaling schemes for cancellation of late time arriving echoes. Signal reflections arriving delayed at the radar when the radar has already emitted a next pulse result in range ambiguities and materialize as potential false targets. In this work we put forward alternative waveform encoding schemes enabling a well-defined radar system to double, triple or quadruple the pulse repetition frequency (PRF) with full suppression of emerging range ambiguities. The proposed techniques thus have the potential to overcome the contradiction often faced in radar and synthetic aperture radar setups between selecting a low or high value for the PRF. The methods introduced require only simple matched filtering operations at the receiver and permit usage of arbitrary waveforms with potential for waveform diversity gains.