Outage performance analysis of millimeter-wave NOMA transmission for line of sight and non-line of sight propagations based on different clustering schemes

Abstract Internet of Things (IoT), as a novel technology, has many challenges that massive connectivity and low latency are two most important of them. Machine to machine (M2M) communication is regarded as a new technology to realize IoT for the 5G wireless networks. In this paper, we are designed a new clustering scheme in a millimeter-wave (mmWave) non-orthogonal multiple access (NOMA) transmission to reduce the system overhead for massive connectivity, which depends on the distance between machine type communication (MTC) device and the base station (BS). The clustering scheme includes a near, a far and a mid-cell MTC device per cluster with a non-overlapping frequency band for both far and mid-cell MTC devices to reduce inter-cluster interference. The proposed three clustering schemes in different conditions are as 1) the random near, the random mid-cell and the random far MTC devices (RNRMRF); 2) the nearest near, the nearest mid-cell and the nearest far MTC devices (NNNMNF); and 3) the nearest near, the farthest mid-cell and the farthest far MTC devices (NNFMFF). The outage probabilities of the clustering schemes are compared analytically for the line of sight paths. Also, the non-line of sight paths for channel gain and the impact of these paths over outage probability are analyzed. The computer numerical and simulation results show the accuracy of the developed analytical and approximation results in high signal-to-noise ratio cases. As a result, our clustering schemes are offered to settle a trade-off between system overhead and outage performance. Besides as an asymptotic computational algorithm, we provided the order of complexity to assess the difficulty of the system.