The carrier phase of cellular signals can be utilized for highly accurate positioning, with the potential for orders-of-magnitude performance improvements compared to standard time-difference-of-arrival positioning. Due to the integer ambiguities, standard performance evaluation tools such as the Cram\'er-Rao bound (CRB) are overly optimistic. In this paper, a new performance bound, called the mixed-integer CRB (MICRB) is introduced that explicitly accounts for this integer ambiguity. While computationally more complex than the standard CRB, the MICRB can accurately predict positioning performance, as verified by numerical simulations, and hence it serves as a useful guide to choose the system parameters that facilitate carrier phase positioning.

翻译：蜂窝信号的载波相位可用于高精度定位，与标准到达时间差定位相比，其性能有望提升数个数量级。由于整数模糊性的存在，标准性能评估工具（如克拉美-罗下界）往往过于乐观。本文提出一种名为混合整数克拉美-罗下界的新性能界，明确考虑了整数模糊性。尽管计算复杂度高于标准克拉美-罗下界，但数值仿真验证表明，混合整数克拉美-罗下界能够准确预测定位性能，因此可作为指导选择有利于载波相位定位系统参数的有效工具。