摘要
This paper studied the application of minimum description length (MDL) criterion for estimating root-mean-squared (RMS) delay spread (RDS) for MIMO OFDM systems. The analytic relationship between the powers and the correlation matrix of multipath components established the feasibility of the application of the MDL criterion to RDS estimation. The estimator presented both the estimate of instantaneous RDS and the estimates of noise variance, channel power and SNR of current channel with low computational complexity. Given the powers of the estimated multipath components, the MDL criterion was adopted to acquire the number of paths and the time delays of each path of current channel without making eigendecomposition of the correlation matrix normally required by MDL criterion, following which the noise variance and the power of each path can be estimated. The power delay profile (PDP) and RDS of the current channel were achieved. Simulation results showed that the proposed estimator was insensitive to variance of SNR and robust against frequency-selectivity.
研究了MIMO OFDM系统中最小描述长度(MDL)准则在均方根时延扩展估计中的应用.分析了多径分量功率和多径分量的自相关矩阵之间的关系,使MDL可有效地应用于RDS估计.该估计器能以较低的计算复杂度给出RDS、噪声方差、信道功率和信噪比等多个实时信道参数的准确估计.根据估计的多径分量功率,利用MDL准则获得了当前信道环境下的路径数及它们各自时延的估计;根据路径数得到了噪声方差和各径功率的估计,从而得到当前信道的功率时延谱和均方根时延扩展的估计.仿真结果表明该估计器可有效对抗信道中信噪比变化和频率选择性的影响.
基金
TheNationalNaturalScienceFoundationofChina(No.60496311).
