基于协作多点下行传输的非线性鲁棒预编码

Nonlinear Robust Precoding for Coordinated Multipoint Downlink Transmission

对于协作多点系统,下行信道信息误差会大幅降低联合传输的性能.为了避免下行信道信息误差对联合传输的影响,本文利用其二阶统计特性,设计了非线性鲁棒预编码算法.由于协作多点系统的特点和非线性鲁棒预编码的结构会导致用户间的性能差异,本文通过优化非线性鲁棒预编码算法的连续干扰消除先后顺序,从而改善性能最差用户的误码率,降低非线性鲁棒预编码算法的平均误码率.仿真结果表明当下行信道信息误差存在时,本文所提出的非线性鲁棒预编码性能优于传统的线性和非线性预编码性能.仿真结果还表明优化排序能提高非线性鲁棒预编码的性能增益.

The performance of the joint transmission in a coordinated multi-point system is bottlenecked by the down- link channel state information errors. To avoid the performance degradation of the joint transmission, a nonlinear robust pre- coding algorithm is proposed, which utilizes the statistical characteristics of the downlink channel state information errors. Due to the feature of the coordinated multi-point system and the structure of the nonlinear robust precoding algorithm, per- formance differences exist among user equipments. To improve the bit error rate of the worst performance user and reduce the average bit error rate of the nonlinear robust precoding algorithm, the order of the successive interference cancellation of the nonlinear robust precoding algorithm is also optimized. Simulation results show that the nonlinear robust precoding algo- rithm proposed in this paper can achieve better performance than the traditional linear and nonlinear precoding algorithms when the downlink channel state information errors exist. Simulation results also show that the ordering optimization can help the nonlinear robust precoding algorithm to attain better performance advantage.