Abstract
In this thesis, we have studied the vector perturbation precoding techniques for MIMO communications [1]. The major contributions of this thesis are in three folds. First, we propose dual modes vector perturbation transmitter based multiuser MIMO systems. The dual modes vector perturbaion transmitter can reduce the number of sphere encoder [1] calls. Second, we propose the vector permutation system for point-to-point MIMO systems and combine the vector permutation with vector perturbation for multi-user MIMO systems with multiple antenna receiver to further reduce the energy of tranmitted signal of vector perturbation system. A searching algorithm of optimal perturbation vector and permutation vector simultaneously by tree search is also proposed. Third, the proposed vector permutation and perturbation is applied to limited feedback system in correlated channel. The proposed vector permutation and perturbation system can combat the degradation of channel correlation. The predefining lookup table is proposed for searching the optimal perturbation and permutation vectors. Finally, we verify the performance of three proposed systems by means of numerical simulations.