Abstract:

To deal with the narrowband interferences in high frequency radar application, sparse frequency waveform allocates its energy into several disjointed bands to obtain a high signa-to-interference-plus-noise ratio (SIR). However, the spectrum discontinuity will result in high range sidelobes. The SIR and sidelobes are coupled in a conflicting way, and should be taken into account together in design, which boils down to multi-objective optimization. The analytical expression of integral sidelobe level (ISL) and SIR under a known interference environment is derived. Then a gradient based iterative algorithm is proposed to obtain the optimum solution to the weighted sum of both metrics. By traveling the weight applied, the Pareto trade off curve is obtained. Using the Pareto trade off curve, waveform design results under different weights are analyzed. The simulation verifies flexibility the optimal design in practical applications.