Sequential optimisation of orthogonal waveforms for MIMO radar

The existing methods to design orthogonal waveforms for multiple‐input multiple‐output radar mainly focus on the optimisation of autocorrelation and cross‐correlation properties. Their performance will degrade severely in the presence of Doppler shifts. To overcome this limitation, the authors take an unknown Doppler shifts range into consideration and formulate a new waveform optimisation problem. Since the optimisation problem is highly non‐linear, the authors propose an algorithm, called sequential cone programming, to tackle it. The key idea is to use the first‐order Taylor expansion to approximate the constraints at each iteration. The authors show that the approximation can be solved via second‐order cone programming. In addition, the autocorrelation peak sidelobe level and cross‐correlation peak level could be further reduced by setting an appropriate threshold function. Simulation results demonstrate the efficiency of the proposed method compared with state‐of‐art methods.