Ambiguity function analysis of Long Term Evolution transmission for passive radar

Long Term Evolution is the 4th cellular technology and has been proved to be a feasible illuminator of opportunity for passive radar. However, ambiguity function within reasonable observation range needs to be thoroughly reconsidered. The ambiguity function of measured LTE signal shows two type of visible sidepeaks, which coincides with ambiguities of simulated Cell-specific Reference Signal and physical control channels based on energy-dominant component analysis. This paper provides an new insight into LTE's ambiguity function, and intrinsic feature of LTE that leads to ambiguities. We'd like to suppress these ambiguities in the near future.