A novel method on designing bispectral windows is proposed in this letter. Compound functions based on a function with binary quadric form, starting from the symmetry characteristic of three-order moments are used as ...A novel method on designing bispectral windows is proposed in this letter. Compound functions based on a function with binary quadric form, starting from the symmetry characteristic of three-order moments are used as the 2-D windowfunctions. Two approaches on how to find the expressions of the compound functions are discussed in detail. One is to approximate the compound function after being Taylor expanded under the Minimum Mean Square Error (MMSE) criteria. Another is to compound the hyperbolic secant function and the binary quadric function directly. According to theoretical analysis, the first type new windows have been proved as slightly better than the conventional ones, the second type new windows are much better than the conventional ones, and the bispectral estimation mean square error approximates to 0.展开更多
Aiming at solving the blind estimation problem of dispreading spectrum sequence under low SNR, a spread-spectrum estimation algorithm based subspace tracking is studied in this paper. This method avoids the direct eig...Aiming at solving the blind estimation problem of dispreading spectrum sequence under low SNR, a spread-spectrum estimation algorithm based subspace tracking is studied in this paper. This method avoids the direct eigen decomposition, using the sliding window technique to obtain the code synchronization, then use segmentation subspace tracking method estimate spreading sequence and splice in a certain order to achieve pseudo-code blind estimation. The results show that the algorithm can complete the accurate estimation of PN code sequence in low SNR conditions, reduce the amount of data storage and be easy hardware implementation展开更多
文摘A novel method on designing bispectral windows is proposed in this letter. Compound functions based on a function with binary quadric form, starting from the symmetry characteristic of three-order moments are used as the 2-D windowfunctions. Two approaches on how to find the expressions of the compound functions are discussed in detail. One is to approximate the compound function after being Taylor expanded under the Minimum Mean Square Error (MMSE) criteria. Another is to compound the hyperbolic secant function and the binary quadric function directly. According to theoretical analysis, the first type new windows have been proved as slightly better than the conventional ones, the second type new windows are much better than the conventional ones, and the bispectral estimation mean square error approximates to 0.
文摘Aiming at solving the blind estimation problem of dispreading spectrum sequence under low SNR, a spread-spectrum estimation algorithm based subspace tracking is studied in this paper. This method avoids the direct eigen decomposition, using the sliding window technique to obtain the code synchronization, then use segmentation subspace tracking method estimate spreading sequence and splice in a certain order to achieve pseudo-code blind estimation. The results show that the algorithm can complete the accurate estimation of PN code sequence in low SNR conditions, reduce the amount of data storage and be easy hardware implementation
