信噪比是衡量信道质量的一个重要参数，该文主要研究LTE(Long Term Evolution)系统中基于探测参考信号(Sounding Reference Signal, SRS)的信噪比估计方法。针对DASS(Difference of Adjacent Subcarrier Signal)算法在高信噪比下噪声估计误差较大的这一缺点，该文提出一种适用于SRS的改进DASS方法。该方法通过重新定义子载波的差分方式，减小了噪声估计的误差，并且由于对连续的3个SRS频点，仅需要估计一次噪声，使得该文方法的复杂度仅为原DASS方法的1/3。仿真结果表明，所提方法的估计性能优于其余的方法，特别是在低时延和中等时延信道下，高信噪比时的估计精度提高了约10倍。
The Signal-to-Noise Ratio (SNR) is an important parameter to measure the quality of the channel, this paper studies SNR estimation method based on Sounding Reference Signal (SRS) in the Long Term Evolution (LTE) system. Since the noise estimation error of Difference of Adjacent Subcarrier Signal (DASS) algorithm is larger in high SNR region, this paper presents an improved DASS method applicable to SRS. By redefining the differential mode of the subcarriers, the estimation error of the noise in this method is reduced, on the other hand, since the three consecutive SRS frequency points only need to estimate noise once, the complexity of the method is only 1/3 of the original DASS method. Simulation results show that the estimated performance of the proposed method is superior to the rest of the method, especially for the low-latency and medium-latency channel, estimation accuracy of the proposed method is improved by about 10 times in high SNR region.