A spatial clustering scheme for downlink beamforming in SDMA mobile radio

We propose a new approach that clusters mobile users before downlink beamforming and broadens beams and nulls within the beamforming calculation. We first investigate the broadening beamforming scheme to alleviate inaccuracies in DOA estimation. Next we exam how to group the mobile users, with the constraint of separation angle, to enhance downlink beamforming. Simulations show that the downlink beamforming complexity is decreased dramatically with limited performance loss.

[1]  Bjorn Ottersten,et al.  The spectrum efficiency of a base station antenna array system for spatially selective transmission , 1995 .

[2]  Josef A. Nossek,et al.  Spatial covariance based downlink beamforming in an SDMA mobile radio system , 1998, IEEE Trans. Commun..

[3]  Josef A. Nossek,et al.  Application of space division multiple access to mobile radio , 1994, 5th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Wireless Networks - Catching the Mobile Future..

[4]  Klaus I. Pedersen,et al.  Spatial channel characteristics in outdoor environments and their impact on BS antenna system performance , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[5]  M. Tangemann.  Near-far effects in adaptive SDMA systems , 1995, Proceedings of 6th International Symposium on Personal, Indoor and Mobile Radio Communications.

[6]  Josef A. Nossek,et al.  On the mobile radio capacity increase through SDMA , 1998, 1998 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.98TH8277).

[7]  Gregori Vázquez,et al.  Robust beamforming for interference rejection in mobile communications , 1996, 1996 8th European Signal Processing Conference (EUSIPCO 1996).

[8]  Ernst Bonek,et al.  Downlink performance of adaptive antennas with null broadening , 1999, 1999 IEEE 49th Vehicular Technology Conference (Cat. No.99CH36363).