Extended ambiguity performance (EAP), which includes all grating lobes and side peaks, indicates the maximum detectable region without undesired peaks for target parameter estimation and is critical to radar sensor design. Driven by EAP requirements of bi-static sensing, we propose design criteria for orthogonal frequency division multiplexing (OFDM) reference signal (RS) patterns. The design not only improves EAP in both time delay and Doppler shift domains under different types of sensing algorithms, but also reduces resource overhead for integrated communication and sensing. With minimal modifications of post-FFT processing for current RS patterns, guard interval is extended beyond conventional cyclic prefix (CP), while maintaining inter-symbol-interference-(ISI)-free delay estimation. For standard-resolution sensing algorithms, a staggering offset of a linear slope that is relatively prime to the RS comb size is suggested. As for super-resolution sensing algorithms, necessary and sufficient conditions of comb RS staggering offsets, plus new patterns synthesized therefrom, are derived for the corresponding achievable EAP. Furthermore, we generalize the RS pattern design criterion for super-resolution sensing algorithms to irregular forms, which minimizes number of resource elements (REs) for associated algorithms to eliminate all side peaks. Starting from staggered comb pattern in current positioning RS, our generalized design eventually removes any regular form for ultimate flexibility. Overall, the proposed techniques are promising to extend the ISI- and ambiguity-free range of distance and speed estimates for radar sensing.

翻译：扩展模糊性能（EAP）包含所有栅瓣与旁瓣峰值，其表征了目标参数估计中不出现干扰峰值的最大可检测区域，对雷达传感器设计至关重要。基于双站感知的EAP需求，本文提出正交频分复用（OFDM）参考信号（RS）模式的设计准则。该设计不仅能在不同类型感知算法下提升时延与多普勒频移域的EAP性能，同时降低通信感知一体化的资源开销。通过对现有RS模式的后FFT处理进行最小化修改，保护间隔可扩展至超出传统循环前缀（CP）的范围，同时保持无符号间干扰（ISI）的时延估计。针对标准分辨率感知算法，建议采用与RS梳状结构尺寸互质的线性斜率交错偏移量。对于超分辨率感知算法，本文推导了梳状RS交错偏移量的充要条件，并基于此合成新信号模式以实现相应的可达成EAP。进一步地，我们将超分辨率感知算法的RS模式设计准则推广至非规则形式，该形式能最小化相关算法消除所有旁瓣所需的资源单元（RE）数量。从现有定位RS的梳状交错模式出发，本文提出的广义设计最终摒弃了所有规则形式以实现终极灵活性。总体而言，所提技术有望扩展雷达感知中距离与速度估计的无ISI及无模糊范围。