Complexity Effective Sequential Detection of Synchronization Signal for Cellular Narrowband IoT Communication Systems

Narrowband Internet of Things (NB-IoT) is one of the most promising low-power wide-area technologies to support low cost, massive connection, deep coverage, and low-power consumption. This article proposes a complexity-effective narrowband secondary synchronization signal (NSSS) detection scheme for the cellular NB-IoT communication system. By taking advantage of the NSSS sequence, the search space of NSSS hypotheses is reduced by decoupling the detection of complementary Walsh sequence and Zadoff–Chu sequence in a sequential manner. Such a detection strategy allows reduced-complexity NSSS detection in the NB-IoT system. Both numerical and simulation results are presented to verify the effectiveness of the proposed NSSS detection scheme. The simulation results show that the proposed NSSS detector achieves a considerable complexity reduction at the cost of some performance degradation, compared to the conventional NSSS detector.