SMSE-based DSA radar waveforms

Previous communications systems research has demonstrated that the Spectrally Modulated, Spectrally Encoded (SMSE) framework is well suited to SDR platforms and operation in both contiguous and non-contiguous spectrum given its ability to generate a wide variety of multicarrier waveforms such as OFDM, NC-OFDM, MC-CDMA, NC-MC-CDMA, CI/MC-CDMA, NCCI/MC-CDMA, and TDCS. In this paper, SMSE waveforms are extended for use in sparse frequency radar systems. Sparse frequency radar can be capable of dynamically sensing available spectrum, and tailoring the transmitted waveforms to suit the instantaneous RF environment conditions, simultaneously transmitting energy in multiple noncontiguous spectrum bands. Conventional radar performance metrics are reviewed, and a new metric is introduced which specifically addresses performance of noncontiguous spectrum waveforms through comparison to contiguous spectrum waveforms. Through simulation, various examples are shown to illustrate and characterize the impairments that are introduced in processing these classes of non-contiguous spectrum waveform returns, specifically the generation of large range sidelobes.