多用户 MIMO 系统中非均匀码本的构建

摘要

在单用户场景下，对于独立同分布的瑞利衰落信道，格拉斯曼码本性能最优。但是该码本不能用于多用户特征波束成形。为了解决上述问题，提出了一种基于最小均方误差准则的非均匀量化码本的构建方法：码本的量化电平数由接收信噪比确定，量化电平值和门限值由信道参数的概率密度函数确定。理论和仿真结果表明：非均匀量化码本相对均匀量化码本的和容量性能大约有3-4dB 的改善、误码率性能大约有2-3dB 的改善。%The Glassman codebook has the best performances in i.i.d Rayleigh fading channel in the single user scenario. It can not be used in multi-user Eigen-Beamforming. In order to solve the problem,we propose an inhomogeneous quantization codebook construction based on MMSE (Minimum Mean Square Error) criterion. The quantization steps are determined by the SNR (Signal to Noise Ratio) at the receiver,while the quantization steps and thresholds depend on the PDF (Probability Density Function) of the channel parameter. The simulation results show that inhomogeneous quantization codebook is about 3-4dB better than homogeneous quantization codebook in the total capacity and about 2-3dB better than homogeneous quantization codebook in the BER (Bit Error Rate).