In this paper the performance of a wireless architecture that enables ultra-broadband wireless transmission is presented. This architecture corresponds to a system with multiple antenna elements on the transmitter and the receiver (MIMO) employing a Spatial Multiplexing technique conforming to the 802.16 (WiMAX) standard. The physical layer performance of this system is assessed by means of MIMO measurements in a home environment. The results are presented and discussed in terms of the Bit-Error-Rate (BER) for a standard and a novel LoS-optimised antenna array architecture.