A Novel Methodology for Spectrally Efficient FMCW Radar Systems

In this letter, we present a novel scheme that compresses the transmit bandwidth of frequency modulated continuous wave (FMCW) radar signal by making use of Barker codes and frequency shifts. The proposed system achieves bandwidth compression where the frequency of the signal is modulated over time using one of the Barker code sequences. Therefore, the changes in the slope of the signal are controlled by Barker codes. To avoid ghost targets, small frequency steps are added at the point of discontinuities. The proposed scheme achieves proportionally superior bandwidth compression at a cost of slightly degraded range resolution. The results are validated by implementation of the scheme on hardware and measuring the bandwidth on a spectrum analyzer. Finally, we jointly optimize spectral efficiency and range resolution to determine the optimal length of the Barker sequence. The resulting flexible design is a huge boost to the applicability of existing FMCW radar systems.