  The mutual interference between similar radar systems can result in reduced
radar sensitivity and increased false alarm rates. To address the synchronous
and asynchronous interference mitigation problems in similar radar systems, we
first propose herein two slow-time coding schemes to modulate the pulses within
a coherent processing interval (CPI) for a single-input-single-output (SISO)
scenario. Specifically, the first coding scheme relies on Doppler shifting and
the second one is devised based on an optimization approach. We further extend
our discussion to the more general case of multiple-input-multiple-output
(MIMO) radars and propose an efficient algorithm to design waveforms to
mitigate mutual interference in such systems. The proposed coding schemes are
computationally efficient in practice and the incorporation of the coding
schemes requires only a slight modification of the existing systems. Our
numerical examples indicate that the proposed coding schemes can reduce the
interference power level in a desired area of the cross-ambiguity function
significantly.
