Radar system with high range-resolution can be obtained through discrete frequency-coding waveform (DFCW). In this paper, we investigate the design process of DFCW using nonlinear chirp (DFCW-NLC), with improved autocorrelation sidelobe peak (ASP) and cross-correlation peak (CCP) levels, to attain radar waveform diversity. In this context, we present a parameterized waveform design model and derive NLC functions for designing the required NLC waveform, thereby simplifying the waveform design process. We derive analytical expressions of autocorrelation and cross-correlation functions for the NLC waveform. To achieve a waveform with desired properties, we present an optimization process based on genetic algorithm, and the optimization of parameterized NLC waveforms attains improved ASP performance over existing designs. Subsequently, we propose the design of a set of DFCW-NLC, double the number as compared to the reported designs. We derive analytical expressions of ambiguity function to investigate waveform performance. We perform a joint optimization of frequency hopping sequence and associated chirp-pulse type of the DFCW-NLC. Numerical results prove that the designed DFCWs-NLC achieve significant improvement in ASP and CCP levels of $\approx 5.0$ dB and $\approx 5.47$ dB, respectively in comparison with the state-of-the-art designs, and makes the proposed waveforms a superior candidate for multiple-input-multiple-output (MIMO) and multiuser radar applications.

通过离散频率编码波形（DFCW）可以获得具有高测距分辨率的雷达系统。在本文中，我们研究了使用非线性chi（DFCW-NLC），具有改善的自相关旁瓣峰（ASP）和互相关峰（CCP）水平的DFCW的设计过程，以实现雷达波形分集。在这种情况下，我们提出了一个参数化的波形设计模型，并推导了用于设计所需NLC波形的NLC函数，从而简化了波形设计过程。我们导出了NLC波形的自相关和互相关函数的解析表达式。为了获得具有所需特性的波形，我们提出了一种基于遗传算法的优化过程，并且与现有设计相比，参数化NLC波形的优化获得了改进的ASP性能。随后，我们提出了一套DFCW-NLC的设计，是报告设计的两倍。我们推导了模糊函数的解析表达式，以研究波形性能。我们对DFCW-NLC的跳频序列和相关的线性调频脉冲类型进行联合优化。数值结果证明，所设计的DFCWs-NLC的ASP和CCP水平显着提高。$\approx 5.0$ 分贝和 $\approx 5.47$ 与现有技术的设计相比，dB分别更高，并且使提出的波形成为多输入多输出（MIMO）和多用户雷达应用的绝佳候选者。