ASER Analysis of Cross QAM for TAS/MRC-MIMO Cooperative Relay System with Imperfect CSI.

In this work, we consider the effect of imperfect channel state information (CSI) for a variable gain amplify-and-forward multi-input and multi-output (MIMO) cooperative system over the generalized Nakagami-m fading channel for 5th generation and beyond systems. In practice, it is not feasible to use dedicated radio frequency chains for each antenna in MIMO system and hence, we employ transmit antenna selection strategy (TAS). TAS being an energy efficient scheme selects an antenna link which maximizes the received signal power. Framework for the generalized average symbol error rate for cross-QAM and square-QAM are provided for TAS based MIMO cooperative system. Impact of system and fading parameters are highlighted over the system performance. Further, Monte-Carlo simulations are performed to validate the derived analytical expressions.