On Impact of Imperfect CSI over SWIPT Device-to-Device (D2D) MIMO Relay Systems

Simultaneous wireless information and power transfer (SWIPT) is an efficient solution for the power scarce wireless communications. In this paper, we consider a relay assisted multi-input and multi-output (MIMO) device-to-device (D2D) communications with a practical scenario of imperfect channel state information (CSI) over a generalized Nakagami-m fading channels. Further, at the relay node, energy from the received radio-frequency (RF) signals is harvested by adopting time-switch (TS) protocol for broadcasting a signal to the destination. In a resource limited environment, it is deterrent to use all the MIMO antennas due to increased system complexity with the dedicated RF chain for each active antenna. Thus, transmit antenna selection strategy (TAS) is considered in this work. Framework for the outage probability and asymptotic outage probability of TAS based MIMO D2D relay system is provided. It is observed that the diversity order of the system gets affected with small variation in imperfect CSI correlation coefficient and throughput of the system gets affected severely with increasing rates with imperfect CSI. Further, Monte-Carlo simulations are performed to validate the derived analytical expressions.