A Spectrum-Edge Detection Approach to Cell Search in LTE

This paper presents a spectrum-edge detection algorithm for initial cell-search in Long-Term Evolution (LTE) wireless networks. The algorithm consists of three steps. First, we roughly identify possible edges in the spectrum. Then, we confirm these “candidate” edges by means of a threshold on the local average spectrum. Finally, the center frequency is precisely determined by searching a pair of edges located at a distance approximately equal to a possible bandwidth of the LTE transmission. Based on tests with field signals, the proposed algorithm is much faster than the conventional sequential cell-search algorithm, where the signal is demodulated for a candidate center frequency and minimum bandwidth: if demodulation is not successful a new candidate center frequency is tried.