Abstract: To improve the orthogonal performance of polyphase sequences of transmitting signals for Multiple-Input Multiple-Output (MIMO) radar, a modified biogeography-based optimization algorithm, POBBO, is proposed for designing orthogonal waveform of polyphase sequences for radar. In this proposed algorithm, the Biogeography-based Optimization algorithm (BBO) is improved. The Habitat Suitability Index (HSI) for individuals is directly adopted to determine the immigration rate and the emigration rate, which significantly simplifies the original method. This reflects the real-time quality for individuals meanwhile shortens the time loss by sorting. Simultaneously, the piecewise logistic chaotic map is introduced to improve the variation mechanism and achieve the effective exploitation for new individuals. In order to obtain the waveform of polyphase sequences with better orthogonal performance, POBBO utilizes the migration and the mutation among the habitats of BBO to interact and improve the HSI. Numerical experiments show that POBBO is competitive with other waveform design algorithms in terms of search accuracy and speed.

Key words: information processing, biogeography-based optimization, orthogonal waveform design, piecewise logistic chaotic map, the immigration rate and the emigration rate