— OFDM multi-carrier modulation is expected to be the enabling technology for 4G wireless systems. One of the features that make OFDM the primary choice for 4G is its MIMO compatibility, because MIMO has a very significant potential of enhancing wireless systems for capacity, data rate, and coverage aspects. In this paper, the challenges of MIMOOFDM measurements are addressed in comparison to SISO, with a special emphasis on WiMAX systems, which employ MIMOOFDM technology. It is proposed to perform the reception and measurement of MIMO-OFDM signals using a single receiver branch rather than multiple receivers. A complete guide to perform impairment estimation for WiMAX MIMO signals with a single receiver according to the 802.16 standards is also provided.
Mustafa E. Sahin, Hüseyin Arslan, Daljeet Sin