论文部分内容阅读
近年来,正交频分复用(OFDM)技术以其在高速数据传输中具有的良好的抗多径衰落的特性以及较高的频谱利用率等优点得到了广泛的应用。在OFDM通信系统中,信号在带宽小于信道相干带宽的多个正交子载波上发射和传输,以克服多径衰落信道所带来的信号频率选择性衰落。为了补偿各个子载波上的多径衰落,这就需要一个性能良好的信道估计方案。对LTE中基于导频的下行信道估计算法进行研究,首先在导频子载波处采用LS(最小二乘法)算法估计出信道参数,然后通过内插的方法在数据子载波处内插得到信道参数。频域内插主要采用拉格朗日内插或是LMMSE(线性最小均方误差)内插;时域内插采用拉格朗日内插。
In recent years, Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used for its advantages of good anti-multipath fading characteristics and high spectral efficiency in high-speed data transmission. In an OFDM communication system, a signal is transmitted and transmitted over a plurality of orthogonal subcarriers having a bandwidth less than a channel coherence bandwidth to overcome signal frequency selective fading caused by multipath fading channels. In order to compensate for multipath fading on each subcarrier, this requires a well-performing channel estimation scheme. The pilot-based downlink channel estimation algorithm in LTE is studied. First, the channel parameters are estimated by LS (Least Squares) algorithm at the pilot subcarriers, and then the channel parameters are interpolated at the data subcarriers by interpolation . Frequency domain interpolation mainly uses Lagrange interpolation or LMMSE (Linear Minimum Mean Square Error) interpolation; time-domain interpolation using Lagrange interpolation.