Transmit beampattern synthesis for MIMO radar using extended circulating code

In multiple-input multiple-output (MIMO) radar settings, it is often desired to transmit power only to a given location or sets of locations defined by the beampattern. Some previous works achieve transmit beampattern synthesis by developing new MIMO radar architectures. In these radar architectures, orthogonal waveforms must be utilised. In fact, the perfect orthogonal waveforms are hardly achievable so that the radar performance loss is inevitable. On the other hand, some waveform design methods, which show superior performance, are proposed. However, the modulus variation and high computational complexity impede their applications in reality. In this study, a simple method for transmit beampattern synthesis is proposed. Based on the circulating code principle, the beampattern synthesis problem has been simplified as a single waveform spectral shaping issue. To solve the spectral shaping issue, an extended circulating code (ECC) with constant modulus is provided. The proposed ECC can achieve an arbitrary beampattern with a single constant modulus waveform while the computational complexity is relatively low. Due to these properties, ECC is simple to apply in practice. The method is evaluated by simulated data and the results can verify its effectiveness.