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

Abstract

This paper describes the performance of transmit antenna selection for an eigenbeam 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. For this 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 eigenbeam scheme with three-select-two antenna selection scheme provides a slight degradation in required carrier-to-noise power ratio (C/N), approximately 0.2 dB from the eigenbeam-only scheme, but with significantly lower computational complexity. Furthermore, with regard to the impact of Doppler frequency, we focus on the transmission interval between MIMO channel estimation and data transmission. To suppress the degradation in required C/N to within 1.5 dB, a transmission interval of approximately 15.0 ms is permitted without using the re-estimation procedure in f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> = 5 Hz, for eigenbeam 16QAM/MIMO-OFDM with three-select-two antenna selection