Implementation of 2x2 MIMO-OFDM System using Universal Software Radio Peripherals

Abstract

Abstract: The 2x1 and 2x2 Multiple Input Multiple Output (MIMO) systems with Orthogonal Space-Time Block Code (OSTBC) are implemented using Universal Software Radio Peripherals (USRPs) and LabVIEW. Bit Error Rate (BER) is estimated and compared for both systems using different Mary Quadrature Amplitude Modulation (QAM) i.e. 4 QAM, 16 QAM, 64 QAM. The BER is reduced for a 2x2 MIMO than a 2x1. To improve spectral efficiency, Orthogonal Frequency Division Multiplexing (OFDM) is combined with MIMO configuration, known as MIMO-OFDM. 2x2 MIMO-OFDM with OSTBC is implemented with M-ary QAM and N IFFT
(32, 64, 128 IFFT). Among these, better BER performance is observed for 2x2 MIMO with 64-IFFT. The MIMO-OFDM is used in Worldwide Interoperability for Microwave Access (WiMAX) which is the standard of IEEE 802.16.
Index Terms: Multiple Input and Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Bit Error Rate (BER), Universal Software Radio Peripheral (USRP)