LTE中一种基于探测参考信号的信噪比估计算法

摘要

为了在上行链路支持频率选择性调度，长期演进(LTE)系统定义了探测参考信号(SRS)用于信道质量估计。该文主要研究SRS的信噪比估计方法，针对Boumard方法和传统DFT方法的缺点，提出一种改进的基于DFT的估计方法。该方法通过在时域修正噪声的估计区间，减小高信噪比时有用信号能量泄露对噪声估计的影响，从而获得更准确的信噪比估计。仿真结果表明，所提方法的估计性能优于Boumard方法和传统的DFT方法，提高了高信噪比时的估计精度，在高信噪比区域，平均估计性能提高了约6 dB以上。%To support frequency selective scheduling in uplink, Long Term Evolution (LTE) system defines the Sounding Reference Signal (SRS) for channel quality estimation. This paper focuses on the Signal-to-Noise Ratio (SNR) estimation of the SRS. In order to deal with the shortcomings of Boumard’s method and the traditional DFT method, an improved estimation method based on DFT is proposed. This method reduces the energy leakage’s influence of useful signal on high SNR by correcting the noise estimated interval in time domain, thus more accurate SNR estimation can be obtained. Simulation results show that the estimated performance of the proposed method is better than Boumard’s method and traditional DFT method, and the average performance achieves an improvement of over 6 dB in high SNR area.