Efficient Sequential Integer CFO and Sector Identity Detection for LTE Cell Search

In this letter, we propose an efficient algorithm for the detection of the integer carrier frequency offset (CFO) and sector identity used in the LTE cell search. For the conventional LTE cell search, the integer CFO and sector identity are jointly detected by utilizing the primary synchronization signal (PSS). By exploiting the symmetric property of the PSS, the integer CFO can be solely detected without the knowledge of sector identity, and thus, the joint detection of the integer CFO and sector identity is decoupled. Additionally, the proposed sequential integer CFO and sector identity detection (SISID) removes the effect of the channel frequency responses such that the detection accuracy is enhanced. We also design the SISID hardware architecture where the parts of the signals are processed in the polar coordinate so that all the multiplications are realized by additions/subtractions. The simulation results demonstrate that the proposed SISID achieves better detection accuracy than the conventional methods with only one third of the computational complexity.