CDMA移动通信系统中基于分组的DBF-MUD

Group-based DBF-MUD in CDMA mobile communication system

为抑制小区内同道干扰,提高系统性能,首先通过波达方向估计把一个小区内的多个用户分成若干组,每组用户一个DBF支路,主瓣对准该组的用户,零陷对准其他组的用户。权矢量与各组用户角度的平均值相对应。各支路DBF输出分别进行MUD,消除组内各用户间的干扰。性能分析和仿真结果证明该方法简化了DBF权值求解,克服了用户空间非正交性,有效降低了系统的误码率。

For the CDMA wireless cellular communication system,a new methodology is proposed to combine digital beamforming（DBF） with multi-user detection（MUD） technology which harnesses the co-channel interference mitigation and obtains better performance.The proposed approach assigns all the users within a cell into separated groups according to their direction of arrival（DOA）.Then,only one DBF branch is employed for a singular group so that the main lobe is steered to the desired users in the group and nulls are directed to the mobile stations in other group.Furthermore,inter-group interference is degraded by MUD following the DBF.The new strategy simplifies the weight vector calculation and solves the unorthogonal channel problem.Additionally,it decreases the bit error rate.The analysis and simulation illustrate the fruits of the new mechanism.