On Bandwidth Efficiency of Massive MIMO Two‐Way Relay Systems in IoT Networks

In modern age wireless communication networks, higher data rates and ultra-improved quality of service is necessary for massive connectivity in Internet of things (IoT) networks. In addition to that the reliability and energy conservation is also required to improve the overall efficiency of the system. The battery lifetime of the communication system can be enhanced by applying simultaneous wireless information and power transfer (SWIPT) technology because it increases the reliability by harvesting the energy from the received signals. The communication range of the IoT sensors can be enhanced by integrating the relay nodes in the system. In this paper, we have considered a two-way relaying system where the relaying node is comprised of large number of antennas and it divides the incoming signals into information decoding (ID) and energy harvesting (EHS) streams. The high rates in this communication system are supported by employing three precoding schemes, that is, maximum ratio transmission (MRT), zero-forcing (ZF) and regularised zero-forcing (RZF). We have considered large-scale fading for massive MIMO channels and SWIPT technique is used for driving the bandwidth efficiency expressions. Furthermore, we have evaluated the analytical through MATLAB simulations.