The multipath effect is the major challenge that deteriorates the high precision and robustness of positioning with global navigation satellite system (GNSS) in urban canyons. It leads to signal attenuation, Doppler shift, time delay, and phase rotation in a coupling manner. In addition, the multipath effect also exhibits the inter-frequency correlation features among different signal bands and types. This work derives theoretical multipath features and quantifies the multi-band multipath correlation. The ray-tracing method with 3D city maps is utilized to construct multipath geometry and conduct multipath characterization. The temporal-frequency multipath spectral analysis on real measurements regarding carrier-to-noise (\(C/{N}_{0}\)), Doppler residuals, and code-minus-carrier (CMC) are provided by using the Hilbert–Huang transform (HHT). To verify the periodic fluctuations and the multi-band correlation in a more realistic situation, the influence of baseband processing is considered and reconstructed. It is confirmed that multipath measurements oscillate at the relative Doppler shift rate, which is proportional to the carrier frequency. This work facilitates multipath identification and mitigation and eventually improves GNSS positioning precision under multipath influence.

多径效应是影响城市峡谷中全球导航卫星系统（GNSS）定位高精度和鲁棒性的主要挑战。它以耦合方式导致信号衰减、多普勒频移、时间延迟和相位旋转。此外，多径效应还表现出不同信号频带和类型之间的频率间相关性特征。这项工作推导了理论多径特征并量化了多频段多径相关性。利用 3D 城市地图的光线追踪方法构建多路径几何并进行多路径表征。使用希尔伯特 (Hilbert) 函数提供有关载噪比 ( \(C/{N}_{0}\) )、多普勒残差和码减载波 (CMC) 的实际测量的时频多径谱分析–黄变换（HHT）。为了验证更真实情况下的周期性波动和多频带相关性，考虑并重构了基带处理的影响。已证实多径测量以相对多普勒频移速率振荡，该速率与载波频率成正比。这项工作有助于多径识别和缓解，并最终提高多径影响下的 GNSS 定位精度。