Order Statistics Based Best Two Transmit Antenna Selection for N × 1 MISO System

In this paper, we analyze the performance of the best two transmit antenna selection (BTTAS) scheme for N×1 multiple-input-single-output (MISO) system employing M-QAM constellation. The exact and asymptotic closed-form expressions of outage probability and symbol error rate (SER) are derived using order statistics over the Rayleigh fading channel for the considered system. This selection technique reduces the complexity and costs of the system associated with multiple transmit antennas while achieving the full diversity order. Further, numerical results show that the proposed BTTAS beamforming scheme achieves full diversity and provides a significant coding gain in comparison to the Alamouti space-time block code.