Implementation and design of physical radar waveform diversity

Echo-locating mammals have been exploiting waveform diversity (WD) for about 50 million years [1], and the notion of radar waveform design has been around for several decades (see [2] and references therein). However, the current instantiation of WD was first popularized in 2002 in the hopes of addressing the growing competition for radar spectrum [3]. Since that time, there has been a tremendous amount of work on myriad aspects of WD (e.g. [4]), with a particular emphasis on leveraging higher dimensionality (e.g., multiple-input multiple-output (MIMO)). Much of this work has focused on the complex mathematical modeling and subsequent optimization of radar “waveforms” (noting that the term tends to be used rather loosely). Here we summarize recent work that seeks to connect the parameterized mathematical abstraction of radar codes, which provide the benefit of being readily optimizable, with the physical attributes and limitations of real radar systems and phenomenology. This physical perspective permits realization of the promised performance enhancements of WD on actual hardware, as well as providing the means with which to address radar spectrum issues for real systems.