In this paper, a new approach is considered for relay aided smart meter to smart meter communication in a microgrid. In the considered framework, a group of smart meters (SMs) simultaneously exchange pricing data with each other for selling or purchasing energy. At the same time, another group of SMs forward load demand and generation information to the control centre as these are the most important states of microgrid for balancing power. The data exchange between SMs and from SM to control centre are aided by a multi-antenna wireless relay, which acts as the communication gateway for the SMs. For the considered system model, the error performance, a key indicator for the reliability of smart grid communication, is analytically derived at the SMs and at the control centre. The analysis indicates that the error performance at the control centre degrades if a large number of SMs communicate with the control centre simultaneously, while the error performance at the SMs does not degrade with increasing number of SMs exchanging data with each other. Finally, the analytically derived error performance is verified using numerical simulations.