DFT-S-GMC系统中均匀导频信道估计方法性能分析

Performance Analysis of Channel Estimation Using Pilots Allocated Evenly for DFT-S-GMC Systems

针对我国提出的离散傅里叶(DFT)扩频广义多载波(DFT-S-GMC)系统,给出了使用均匀分布导频的信道估计方法。该方法首先采用最小二乘算法估计导频音的信道频响,然后内插或外推非导频音的信道频响,再利用信道频响DFT过采样特性,数据块特定用户数据子带信道频响可由与之对应的导频块内子载波处信道频响线性内插获得,并在时间维上线性内插出数据子带处的信道频响。最后,通过仿真比较分析了高低阶插值、内插外推方法以及导频密度对信道估计方法性能的影响。

For the DFT spreading generalized multi - carrier （DFY- S - GMC） system proposed by China, the channel estimation method using pilots allocated evenly is proposed. Firstly, the channel frequency responses （CFRs） at the pilot tones are estimated as a rule of least square, which are utilized to interpolate or extrapolate the CFRs at the other frequency tones. Then, by exploiting the DFT oversampling characteristics, the CFRs at the user- specified date subbands of the data block can be obtained by interpolating linearly the channel esti- mates at the subcarriers positions of the pilot block corresponding to the data subbands. Finally, the channel es- timates at the specified data subbands can be interpolated linearly in the time dimension by the estimated CFRs above. The influence of high or low order interpolation and extrapolation, and the pilot density on channel esti- mation are analysed and compared by simulations.