这是一篇很好的有关信道估计的文章，

可以用来快速的了解信道估计的基本内容-In this paper, a method for fast blind estimation

of DS-SS signal is proposed which aims at the

Direct-Sequence Spread- Spectrum (DS-SS) signals

with parameters unknown. Considering the

characteristic that Pseudo-Random noise (PN)

sequence modulates the information symbol, we

make use of the method based on the second-order

cyclic-cumulant to estimate the period of PN

sequence, and then the method of segmented

cross-correlation to estimate the synchronous start

bit between the information symbols and the PN

codes. On base of this, a method of multiple

subsection cross-correlation average is used to

estimate the PN sequence. Computer simulations

show that the method can work well on signals at

low signal noise ratio (SNR).