Initial timing acquisition in narrow-band IoT (NB-IoT) devices is done by detecting a periodically transmitted known sequence. The detection has to be done at lowest possible latency, because the RF-transceiver, which dominates downlink power consumption of an NB-IoT modem, has to be turned on throughout this time. Auto-correlation detectors show low computational complexity from a signal processing point of view at the price of a higher detection latency. In contrast a maximum likelihood cross-correlation detector achieves low latency at a higher complexity as shown in this paper. We present a hardware implementation of the maximum likelihood cross-correlation detection. The detector achieves an average detection latency which is a factor of two below that of an auto-correlation method and is able to reduce the required energy per timing acquisition by up to 34%.
@article{arxiv.1608.02427,
title = {Maximum-Likelihood Detection for Energy-Efficient Timing Acquisition in NB-IoT},
author = {Harald Kroll and Matthias Korb and Benjamin Weber and Samuel Willi and Qiuting Huang},
journal= {arXiv preprint arXiv:1608.02427},
year = {2016}
}
Comments
5 pages, 6 figures, submitted to M2M Communications and the Internet of Things workshop at WCNC 2017