Two algorithms for spread-spectrum sequence estimation for DSSS signals in non-cooperative communication systems

Two estimation algorithms for the spreading sequence in DSSS signals are proposed. Some of previously proposed algorithms have some drawbacks such as large computational complexity, low estimation accuracy and poor accuracy by increasing the length of spreading sequence period. In this paper by using an initial estimate of chips, we can improve recursively the final decision with low computational complexity. The results show that our proposed algorithms have better estimation accuracy even for large number of chips.