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In this paper, we consider the unimodular sequence generation problem, and the sequences are required to possess both spectrum compatibility in the reverberant electromagnetic environment and low sidelobe levels of autocorrelation function (ACF). We proposed a template fitting approach based on the templates which define the spectrum compatibility requirements and sidelobe level requirements. First, we established the templates based on the actual sequence-feature requirements in the changing crowed-spectrum and clutter environment. Second, given an initial sequence, the spectrum shapes and the ACF features of generated sequences of proposed algorithm will approach those of templates by iterative process. Third, the iteration process come to end if the figure of merit shows convergence or meets specific requirements. The superiority of this approach is its calculation effectiveness. Specifically, it is capable of generating sequences with required power spectrum density (PSD) and ACF behaviors within much less computation load compared with some typical algorithms in open literature. Finally, some simulation results are provided to compare the spectrum compatibility and/or sidelobe suppression performance with that of SCAN (stopband cyclic algorithm new) and WeCAN (weighted cyclic algorithm new) algorithm, which prove the calculation and performance effectiveness of the proposed approach. HighlightsA template based technique for unimodular sequence design problem is proposed.The sequence is designed to consider sidelobe suppression and spectrum compatibility.The PSD and ACF templates are defined cognitively to meet the theme requirements.The TFA algorithm induces the PSD and ACF of sequences to converge to the templates.The TFA algorithm shows effectiveness in both performance and calculation aspects.

One of the important obstacles in MIMO (Multiple Input Multiple Output) radars is the issue of designing proper transmit signals. Indeed, the capability of signal design is a significant advantage in MIMO radars, through which, the system can achieve much better performance. Many different aspects of this performance improvement have been considered yet, and the transmit signals have been designed to attain such goal, e.g., getting higher SNR or better detector's performance at the receiver. However, an important tool for evaluating the radar's performance is its ambiguity function. In this paper, we consider the problem of transmit signal design, in order to optimize the ambiguity function of a distributed MIMO radar system via maximizing its peak. HighlightsTransmit signals are designed to maximize the ambiguity function's peak of a WS-MIMO radar.Signal design is done for three cases of single target, multi-target, and prioritized ambiguity function.It is shown that in spite of increasing the number of antennas of MIMO radar, signal design does not provide diversity gain.Through simulations, it is shown that better performance can be achieved by the proposed signal design to maximize the AF's peak.