共轭先验的零前缀OFDM系统信道估计

Channel Estimation Using Conjugate Priors for ZP-OFDM Systems

提出了一种利用共轭先验信息的零前缀(Zero Padding,ZP)正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统信道估计的方法.首先,由于零前缀的使用,可将信道矩阵替换成循环矩阵,然后接收端信号左乘快速傅里叶变换(Fast Fourier Transformation,FFT)矩阵将该循环矩阵对角化,这时使用盲信号分离技术只需要寻找一个对角矩阵,减少了计算量.其次,充分利用对角矩阵的先验信息,在目标函数中增加上述对角矩阵的稀疏性度量,提高了信道估计的效率和准确性.仿真结果表明:相比于传统的直接分离接收端信号的方法,该方法计算量小,收敛速度快.

This paper proposes a novel channel estimation method for zero padding （ ZP ） OFDM using conjugate prior. First, the channel matrix can be seen as a circulant matrix thanks to the zero padding. Then with adopting blind signal separation （ BSS） technique, we only need to obtain a diagonal matrix after diago-nalizing the circulant matrix by pre-multiplication the received signals by an IFFT matrix, which greatly re-duces the computational complexity. Moreover, sparse priors on the diagonal matrix is added to objective function in order to improve the efficiency and accuracy of channel estimation. The proposed approach is con-firmed that has lower complexity, faster convergence by computer simulations, compared with the traditional algorithm which directly separating the received signals.