Experimental Evaluation of Transmit Antenna Selection Implemented in FPGA for MIMO-OFDM

This paper describes the experimental performance of transmit antenna selection in a multiple-input multiple-output with orthogonal frequency division multiplexing (MIMO-OFDM) system as measured in a testbed implemented with field programmable gate array (FPGA); it also targets wireless LANs. In this experimental verification, we employ the determinant-based transmit antenna selection approach based on the estimated instantaneous MIMO channel matrix to reduce the computational complexity. The measured packet error rate (PER) performance confirms that the antenna selection scheme provides an approximately 3.5 dB improvement in the required carrier-to-noise power ratio (CNR) of 16 QAM/MIMO-OFDM. Furthermore, with regard to the impact of Doppler frequency f_d, we focus on the transmission interval between the MIMO channel estimation and data transmission. To suppress the degradation in required CNR to within 1.0 dB, a transmission interval of approximately 13.3 ms is permitted without using the re-estimation procedure in f_d=5 Hz, QPSK/MIMO-OFDM.