同步多用户长码直扩信号的盲解扩

摘要

In this paper, a blind despreading algorithm is proposed for the synchronous multi-user long-code Direct Sequence Spread Spectrum (DS-SS) signals in low Signal to Noise Ratio (SNR) scenarios. The synchronous multi-user long-code DS-SS signals are represented as the short-code ones with missing data, and then the users' spreading waveform subspace is estimated by the Singular Value Thresholding (SVT) algorithm. Finally, the Expectation Maximization (EM) algorithm is used to blindly despread the signals. The simulations show that the proposed algorithm has nearly performance with the cooperative dispreading in low-SNR scenarios.%针对同步多用户长码直扩信号,该文提出了一种低信噪比条件下的盲解扩算法.该算法通过将多用户长码直扩信号建模为含有缺失数据的同步多用户短码直扩信号,采用SVT算法实现扩频码波形序列子空间估计,并在此基础上利用EM算法完成信号的盲解扩.计算机仿真表明即使在较低信噪比条件下,该算法也具有优良的盲解扩性能,且与合作解扩性能相近.