Low-Complexity Channel Estimation based on Conjugate Gradient
Chenyan Li · Communications technology · 2015
In consideration of pilot-based channel estimation in large-scale MIMO( Multiple-Input Multiple-Output) communication systems,hundreds of antennas are equipped at the base station. Conventional MMSE estimator enjoys good performance in the estimation accuracy,and however,when MMSE channel estimation method is used to implement estimation,the operation of covariance matrix inversion would result in computational complexity of O(M3),M meaning the dimension of channel covariance matrix,and when the base station is equipped with hundreds of antennas,this would be an extremely complex process. To solve this problem,the inversion process is transformed into solution of linear equations,thus the computation complexity of the whole process is reduced to O( NM2) through conjugate gradient method,N meaning the iterations number of conjugate gradient algorithm and NM.