大规模3D MIMO中基于信道相关的LOS/NLOS识别算法

Channel Correlation Based LOS/NLOS Identification for 3D Massive MIMO Systems

为了提高易受视距(LOS)和非视距(NLOS)传输影响无线应用的性能,对大规模三维多输入多输出(3D MIMO)系统中的LOS/NLOS识别进行了研究,针对实际场景,采用实际信道而非通常假设的理想准确信道,提出了一种改进的时-空-频信道相关识别算法TSFCI-1.识别过程包括3个阶段:根据LOS/NLOS用户不同的时-空-频特性定义测量;针对大规模3D MIMO中信道空间相关性不平稳的特点,对评价指标在空间间隔上求期望;使用时域信道信息进行建模和识别.在此基础上,考虑到天线双极化的影响,改进评价指标,并提出算法TSFCI-2.仿真结果表明,TSFCI-1和TSFCI-2的算法性能均优于对比算法6%以上,错误率分别低至1.92%和1.72%.此外,讨论了信噪比和时域径数对表现最好的TSFCI-2性能的影响.

To improve the performance of some wireless technologies,which are susceptible to line of sight(LOS)and non line of sight(NLOS),LOS/NLOS identification in 3D massive multi-input multioutput(MIMO)system is studied.Based on channel correlation,an improved identification algorithm,TSFCI-1,is proposed,which uses actual channel information instead of the normally assumed ideal accurate channel.The process includes:defining measurement based on time-space-frequency properties of LOS/NLOS;in view of the unsteady spatial channel correlation for 3D massive MIMO systems,finding the expectation of measurement on the spatial interval;using channel information to construct the statistical identification model.Considering the influence of antenna dual-polarization,TSFCI-2 with better evaluation index is proposed.It is shown that the identification error of TSFCI-1 and TSFCI-2 is as low as1.92%and 1.72%,with over 6%better than a previous study.Besides,the effects of signal to noise ratio and the taps number on TSFCI-2 with the best performance is discussed.