This paper is to examine about approximate antenna selection (AS) strategies for bi-directional full duplex Multiple Input multiple Output(MIMO) structures in which the antenna node can be decided on both to transmit or to receive. The technique used here is finding the best antenna set solution from all the available antennas primarily by analysing the average sum rate of optimal AS. This result provide which all antennas from the receiver side to the transmitter side configuration gains the average sum rate of the performance. This is followed by the introduction of a new AS algorithm with optimal rate of average sum that is near to the AS scheme but with reduce complexity.

Keywords : MIMO systems, AS scheme.