Algorithms for delay estimation and tracking in CDMA

For estimating delay parameters appearing in the CDMA (code division multiple access) model, several authors have proposed subspace-based solutions. Unfortunately, these methods, for example the eigenvector-based multiple signal classification (MUSIC) method may yield poor results in noisy conditions. In this paper, we introduce subspace type delay estimation algorithms which are more efficient than MUSIC. One approach is an optimal reference method, which assumes prior knowledge of the fadings and symbols