Mitigation of autocorrelation sidelobe peaks of orthogonal discrete frequency-coding waveform for MIMO radar

The autocorrelation sidelobe peak (ASP) levels of discrete frequency-coding waveform with fixed frequency pulses (DFCW_FF) is very large. It is about 0.21 or -13.2dB. Replacing the fixed frequency pulses with linear FM pulses (LFM) can lower the ASP. We investigate theambiguity function (AF) and cross-AF for DFCW with arbitrary frequency firing order. It shows that DFCW_LFM have different AF expression with the DFCW_FF. By setting the relationships between the Deltaf, B and T, we can reduce the ASP, as well as nullify the grating lobes. A modified Genetic Algorithm (GA) is proposed to numerically search orthogonal DFCW_LFM with optimal correlation properties. Some of the designed results are presented. Their correlation properties are effectively improved. Both simulation results and comparisons show that the method of mitigating ASP and proposed search algorithm are effective for the design of DFCWs with superior aperiodic correlation.