Massive Uncoordinated Multiple Access for Beyond 5G

Existing wireless communication systems have been mainly designed to provide substantial gain in terms of data rates. However, 5G and Beyond will depart from this scheme, with the objective not only services higher One main goals is support massive machine-type communications (mMTC) Internet-of-Things (IoT) applications. Supporting uplink for devices sporadic traffic pattern short-packet size, as it many mMTC use cases, a challenging task, particularly when control signaling negligible size compared payload. In addition, channel estimation becomes transmission due limited number employed pilots. paper, new multiple access (MA) scheme proposed mMTC, which can large uncoordinated IoT traffic. The MA removes overheads associated device identifier well pilots preambles related estimation. An alternative mechanism identification (DI) employed, where unique spreading code dedicated each identifier. This simultaneously used purpose DI. Two DI algorithms employ sparse signal reconstruction methods are determine active prior detection. Specifically, Bayesian information criterion model order selection method develop an algorithm unknown time-varying activity rate. Our benefits non-coherent nonlinear multiuser detection on basis unsupervised machine learning techniques enable without a priori knowledge state information. For performance improvement, extension receive antennas through hard decision combining proposed. effectiveness known rate high overloading factor supported by simulation results.