Phase-modulated continuous-wave (PMCW) radar is an emerging technology in various civilian applications. Due to the high bandwidth of the PMCW signal, it needs high-speed analog-to-digital converters (ADCs). High-resolution ADCs supporting this high bandwidth are expensive, have a big size on the chip, and consume high power, which are significant challenges for radar. A solution to deal with the aforementioned challenges is to use low-resolution, or in the most extreme case, one-bit ADCs. In this article, we aim at designing the transmit code and the receive filter for the PMCW radar in the presence of one-bit ADC at the receiver side. To this end, we introduce the mean integrated sidelobe level metric, called MISL. MISL generalizes the well-known ISL metric for nonideal ADC usage at the receiver side and takes the effect of noise and target backscattering coefficient into account. For mathematical tractability, we employ the maximum likelihood estimation of the target backscattering coefficient. This leads to casting an optimization problem that does not need knowledge about noise and target characteristics. We utilize the cyclic optimization procedure to optimize the transmit code and the receive filter. The filter design subproblem admits a closed-form solution, whereas we obtain a solution to transmit code design subproblem via the coordinate descent framework. Numerical examples illustrate the superior performance of the proposed method compared to benchmarks that design sequences assuming ideal ADC at the receiver.

中文翻译：

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存在一位 ADC 的 PMCW 雷达的发送代码和接收滤波器设计


相位调制连续波（PMCW）雷达是各种民用应用中的一项新兴技术。由于 PMCW 信号的高带宽，它需要高速模数转换器 (ADC)。支持如此高带宽的高分辨率 ADC 价格昂贵、芯片尺寸大、功耗高，这对雷达来说是重大挑战。应对上述挑战的一个解决方案是使用低分辨率，或者在最极端的情况下，使用一位 ADC。在本文中，我们的目标是在接收器侧存在一位 ADC 的情况下设计 PMCW 雷达的发射代码和接收滤波器。为此，我们引入了平均集成旁瓣电平度量，称为 MISL。 MISL 概括了接收器端非理想 ADC 使用的众所周知的 ISL 指标，并考虑了噪声和目标反向散射系数的影响。为了数学上的易处理性，我们采用目标后向散射系数的最大似然估计。这导致提出一个不需要有关噪声和目标特征的知识的优化问题。我们利用循环优化过程来优化发送代码和接收滤波器。滤波器设计子问题承认封闭式解，而我们通过坐标下降框架获得了传输代码设计子问题的解。数值示例说明了与假设接收器处理想 ADC 设计序列的基准相比，所提出的方法具有优越的性能。