In this paper, a novel adaptive physical-layer identity detection algorithm for LTE systems is presented. The proposed algorithm can estimate the location of the primary synchronization signal (PSS) and detect the physical-layer identity in the presence of jamming or interference. Multiple parallel adaptive filters are used to suppress the jamming signal without using any a priori information about its characteristics. Each filter is designed using the linearly constrained minimum variance (LCMV) criterion to minimize the output corresponding to any received signal that does not match the signature of the PSS. The frequency response of the adaptive filters at the PSS timing detection instant is used to suppress the interference/jamming signal during physical-layer identity estimation. Simulation results are presented to illustrate the superior performance of the proposed algorithm compared to earlier non- adaptive PSS detection algorithms.