A Method for Blind Estimation of PN Sequence of Short-Code and Periodic Long-Code DSSS Signal
Fenghua Wang · Journal of Astronautics · 2011
A new method to blindly estimate the PN sequence of short-code(SC) and periodic long-code(PLC) direct sequence spread spectrum signals(DS-SS) is presented in this paper.The PLC DSSS signal is modeled as an multi-user short-code DSSS system.The information rate is blindly estimated according to the number of information symbols modulated during a period of spreading sequence according to the number of eigen-values of the received signal correlation matrices.This enables us to exploit an improved second order blind identification(SOBI) to estimate users' spreading sequence,and make use of special constraint condition(such as m-or Gold-sequence) to eliminate the phase ambiguity,and form the blind estimation of long-code PN sequence lastly.Simulations show that the proposed method can provide a good estimation for all kinds DSSS signals in non-cooperative context,even in low signal-to-noise(SNR).