The Unambiguous Distance in a Phase-based Ranging System with Hopping   Frequencies
  It is a challenge to specify unambiguous distance (UD) in a phase-based ranging system with hopping frequencies (PRSHF). In this letter, we propose to characterize the UD in a PRSHF by the probability that it takes on its maximum value. We obtain a very simple and elegant expression of the probability with growth estimation techniques from analytic number theory. It is revealed that the UD in a PRSHF usually takes on the maximum value with as few as 10 frequencies in measurement, almost independent of the specific distribution of available bandwidth. 
Yue Zhang, Wangdong Qi and Su Zhang
cs.OH