Tongxin xuebao (Oct 2018)
Blind estimation of spreading codes for multi-antenna LC-DS-CDMA signals based on tensor decomposition
Abstract
Aiming at the problem of the poor performance of the imputation method for the spreading codes blind estimation of the multi-antenna long-code direct sequence code division multiple access (CDMA) signals.Firstly,using the segmentation idea,the received signals were constructed into a three-dimensional tensor model,and the tensor was divided into sub-tensors according to the spreading gain.The sub-tensors were constructed into the Tucker decomposition model.Secondly,the spreading code fragments and the receiver gain matrixes were obtained from the sub-tensors by Tucker decomposition which was using the variable step gradient descending algorithm.Then,because of the same characteristic of the receiver gain matrixes in each sub-tensor,the permutation matrixes were estimated by using the cross correlation matrixes of the receiver gain matrixes and the order of the spreading code fragments was corrected.Finally,the amplitude of the spreading codes was determined by using the autocorrelation of the spreading codes,and each user’s spreading code was obtained.The simulation results verify the effectiveness of the proposed algorithm.
