Collision-Tolerant Narrowband Communication Using Non-Orthogonal Modulation and Multiple Access

Ultra Narrowband (UNB) has recently received great attention for its potential to realize ultra- reliable, massive scale Low Power Wide Area Networks (LPWAN). Elaborate frequency planning and multiple access schemes have been regarded as an essential part of LPWAN because random frequency- and time-domain ALOHA accesses lead to significant network performance degradation due to inevitable packet collisions. In this paper, we propose a novel network scheme based on non-orthogonal modulation and multiple access (NOMMA) that is tolerant to packet collisions. The proposed scheme uses hyper-dimensional modulation (HDM) to outperform conventional orthogonal modulation and multiple access schemes with and without prior knowledge of interference in highly congested network scenarios. Simulation results show that HDM based NOMMA can achieve 70% higher network throughput than a conventional orthogonal modulation and multiple access scheme.