The main limitations of wireless transmission are fading and associated reduction in bit error rate. To mitigate these effects several techniques are employed. It is well known that the performance of the wireless communication systems can be enhanced by using multiple transmit and receive antennas, which is generally referred to as the MIMO technique. This has been incorporated into the IEEE 802.11n standard. The MIMO technique has also been adopted by the 3GPP Long Term Evolution (LTE) and the 3GPP2 Ultra Mobile Broadband (UMB) standards.