A polynomial rooting approach for synchronization in multipath channels using antenna arrays
G. Seco, Arnold Lee Swindlehurst, Juan A. Fernandez–Rubio · 2005
The estimation of the delay of a known training signal re-ceived by an antenna array in a multipath channel is ad-dressed. The eect of the co-channel interference is taken into account by including a term with unknown spatial cor-relation. The channel is modeled as an unstructured FIR lter. The exact maximum likelihood (ML) solution for this problem is derived, but it does not have a simple de-pendence on the delay. An approximate estimator that is asymptotically equivalent to the exact one is presented. Us-ing an appropriate reparameterization, it is shown that the delay estimate is obtained by rooting a low-order polyno-mial, which may be of interest in applications where fast feedforward synchronization is needed. 1.