| 摘要: |
| 针对移动WiMAX下行系统中导频个数少且分配不均匀导致的边缘效应问题，提出了一种
基于奇异值分解（SVD）的快速傅里叶变换（FFT）内插信道估计方法。该方法首先得到每个
符号实
际分配导频处的最小二乘信道频响估计，当前符号在相邻符号实际分配导频处的信道频响由
相邻符号信道频响线性内插得到；然后，将上述信道估计值合并且按子载波索引值升序排列
后进行奇异值FFT内插，以减少边缘效应和噪声的影响；最后再经线性内插得到数据子载波
处的信道频响估计值。仿真结果表明，和传统估计方法相比，所提出的方法估计精度更高，
复杂度较低，而且避免了使用信道统计特性信息。 |
| 关键词: 移动WiMAX 信道估计 FFT内插 奇异值分解 边缘效应 |
| DOI： |
|
| 基金项目:国家自然科学基金资助项目(61040010)；河南科技大学
博士科研启动基金资助项目(09001409)；河南科技大学青年科学基金资助项目(2010QN0019)
；河南省科技攻关计划项目(112102210431) |
|
| Channel Estimation Based on SVD Aided FFT Interpolation for Mobile WiMAX Downlink Systems |
| WANG Dan,YANG Lei |
| (Electronic Information Engineering College,Henan University of Science and Tec
hnology,Luoyang 471003,China) |
| Abstract: |
| This paper proposes a channel estimation method based on singular valu
e decomposition(SVD) aided FFT interpolation for mobile WiMAX downlink systems,
in order to overcome the border effect incurred by the limited number and irreg
ular spacing of pilots. Firstly, the proposed method estimates the channel frequ
ency response based on least square(LS) criterion at its own pilot tones of eac
h symbol. Secondly, the channel estimates of each symbol can be interpolated lin
early at the pilot positions where its adjacent symbol allocates the pilots. Thi
rdly, the LS channel estimates above are combined with the interpolated channel
estimates and then are sorted in an ascending order of the pilot subcarrier inde
xes. The combined and sorted channel estimates are interpolated by the FFT based
on SVD to reduce the border effect and the noise impact. Finally, the interpola
ted channel estimates based on SVD-FFT are utilized for interpolating the channe
l on the remained data subcarriers linearly. Simulations demonstrate that, compa
red with the existing methods, the proposed method not only has a better estimat
io
n performance and a lower computational complexity, but also avoids using the ch
annel statistics. |
| Key words: mobile WiMAX channel estimation FFT interpolation singular value decompositio
n border effect |
