An Effective MIMO-OFDM Transmission Scheme for IEEE 802.22 WRAN Systems

In this paper, we propose a closed-loop MIMO-OFDM (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) transmission scheme that is appropriate for the IEEE 802.22 WRAN (Wireless Regional Area Network) channel environments. The proposed scheme utilizes the Grassmannian beamforming and an antenna selection algorithm proposed by the authors to maintain BER (Bit Error Rate) performance and to reduce feedback information. To further reduce the feedback information considering channel property of the IEEE 802.22 WRAN, the proposed scheme employs an extension of the feedback period. Simulation results in the IEEE 802.22 WRAN reference channel models indicate that the proposed MIMO-OFDM transmission scheme achieves superior BER performance and spectral efficiency than open-loop MIMOq-OFDM system even considering the feedback overhead of the system.