Multiuser processing, using an antenna array, has emerged as a suitable solution for capacity increase in wireless systems. The use of an antenna array reduces the multiuser interference, allowing two or more users to share systems resources in an efficient way. The use of a Linearly Constrained Minimum Variance (LCMV) criterion to optimize the antenna array weights has been proved to be a good solution for multiuser processing. This work presents an unified view of LCMV beamforming, including a solution that avoids direction of arrival (DOA) estimation and is able to cope with angular spread. An adaptive versions of the resulting technique is also presented. Moreover, we evaluate the performance of the proposed techniques in non-zero angular spread and non-stationary environments. The results provide an overview of the potential of LCMV techniques in multiuser wireless communication systems. © 2007 IEEE. 521525Filho, D.Z., Cavalcante, C.C., Romano, J.M.T., Resende, L.S., An LCMV-Based Approach for Downlink Beamforming in FDD Systems in Presence of Angular Spread (2002) EUSIPCO 2002, , Toulouse, France, SeptemberFilho, D.Z., Cavalcante, C.C., Romano, J.M.T., Adaptive LCMV Beamforming Avoiding DOA Estimation for Packet-like Wireless Systems (2002) IEEE International Telecommunications Symposium (ITS'2002), , Natal-RN, Brazil, SeptemberZetterberg, P., Mobile cellular communications with base station antenna arrays: Spectrum efficiency, algorithms and propagation models, (1997), Ph.D. dissertation, Royal Institute of Technology, Stockholm, SwedenFrost III, O.L., An Algorithm for Linearly Constrained Adaptive Array Processing (1972) Proceedings of the IEEE, 60 (8), pp. 926-935. , AugustBuckley, K.M., Spatial/Spectral Filtering with Linearly Constrained Minimum Variance Beamformers (1987) IEEE Trans. on ASSP, 35 (3), pp. 249-275. , MarchResende, L.S., Romano, J.M.T., Bellanger, M.G., A Fast Least-Squares Algorithm for Linearly Constrained Adaptive Filtering (1996) IEEE Trans. on Signal Processing, 44 (5), pp. 1168-1174. , MayHaykin, S., (1996) Adaptive Filter Theory, , 3rd ed. Prentice HallCavalcanti, F.R.P., Smart Antennas and Space-Time Processing for Wireless Communication Systems, (1999), Ph.D. dissertation, State University of Campinas UNICAMP, Campinas, SP, Brazil, July