协作多点传输中基于空间协方差动态更新的码本自适应方法

An Codebook Adaption Method Based on Dynamic-Updated Spatial Covariance for CoMP

针对典型码本自适应算法的信道协方差矩阵反馈时间间隔过长,导致高速环境下系统性能迅速恶化的缺点,提出了一种基于信道协方差矩阵动态更新的码本自适应改进算法。基于协方差矩阵和码本之间的等效关系和均方误差最小的原则,在接收端将协方差矩阵拆分成一个固定参数和一个码本向量,并向发射端反馈该码本向量。然后,在发射端利用反馈的码本向量及本地固定参数和上一时刻的协方差矩阵,重构当前时刻的协方差矩阵。仿真结果表明,较之典型算法,提出的算法具有更好的性能表现,尤其在高速环境下,可以获得近2dB的增益。

Owning to the fact that the large interval of feedback in classic codebook adaptation leads to a sharp performance decrease in high-speed scenarios, the improved codebook adaptation is proposed based on the dynamically-updating of spatial covariance. At the receiver, a codebook index and a variable are obtained by the decomposition of the covariance matrix on the basis of the rela- tionship between the codebook and spatial covariance and the MMSE criterion, which would be fed back to the transmitter. At the transmitter, the terms fed back from the receiver and the previous covariances are used to reconstruct the current covariance matrix. Referring to the simulation results, the proposed have a better performance compared with the classic algorithm, especially in the high-speed scenarios where could have almost 2dB gain.