MIMO Eigen Beamforming for HSUPA of TD SCDMA

As the evolution of the 3G standards, multiple input and multiple output (MIMO) has been adopted to enhance the performance of 3G systems for the potential of beamforming, spatial multiplexing or spatial diversity. So far, no MIMO scheme has been adopted for time division-synchronous code division multiple access (TD-SCDMA). In this paper, 2times8 MIMO eigen beamforming is proposed to improve the performance of TD-SCDMA. As size limited, the antennas at the UE or Node B are correlated, only one eigen mode of the spatial correlation matrix is found to be useful, and only the beamforming gain and spatial diversity gain can be obtained efficiently. The simulation results of high speed uplink packet access (HSUPA) in the fixed reference channel show that, compared to single input and multiple output (SIMO) 1times8, 3 dB performance gain can be obtained by MIMO 2times8 eigen beamforming; while compared to that of single input and single output (SISO), the performance gain is 8-3 dB