OFDM無線通信4G基礎Broadband MIMO-OFDM Wireless CommunicationsBroadband MIMO-OFDM Wireless Communications GORDON L. STBER, FELLOW, IEEE, JOHN R. BARRY, MEMBER, IEEE, STEVE W. MCLAUGHLIN, SENIOR MEMBER, IEEE, YE (GEOFFREY) LI, SENIOR MEMBER, IEEE, MARY ANN INGRAM, SENIOR MEMBER, IEEE, AND THOMAS G. PRATT, MEMBER, IEEE Invited Paper Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and/or to enhance the system capacity on time-variant and frequency-selective channels, resulting in a multiple-input multiple-output (MIMO) configuration. This paper explores various physical layer research challenges in MIMO-OFDM system design, including physical channel measurements and modeling, analog beam……