I Introduction
Multiple-input multiple-output (MIMO) communication systems[1] constitute the basis for many upcoming wireless communication standards (e.g., IEEE 802.11n) and offer increased spectral efficiency (compared to single-antenna systems) by transmitting multiple data streams concurrently in the same frequency band. Matrix decomposition algorithms [2], such as the singular value decomposition (SVD) or the QR decomposition (QRD), have applications in various signal processing fields. The SVD, for example, is used in array processingor data compression, but can also be applied to MIMO systems in order to increase the system performance by the use of beamforming and power allocation. The QRD, for example, is a key prerequisite for many advanced MIMO detectors, such as the sphere decoder [3].