Multiresolutive acquisition technique for DS-SS long-haul HF data link

In this paper a study of the multiresolutive acquisition and tracking structure proposed in [8] for a multipath and time variant long ionospheric channel is presented. The multiresolutive structure is adaptive-based, using LMS algorithms over the received signal at chip rate sampling, and converges to the correct acquisition point using a decimated version of the pseudonoise sequence as a reference, achieving a reduction of the computational load of the digital receiver. It uses the Gold pseudonoise sequences family regarding its good crosscorrelation vs. autocorrelation balance properties as in future work a multiuser transmission will be tested. Pseudonoise sequence phase tracking is also solved using the multiresolutive structure, so the estimation of the acquisition point is given by the structure. The results in this paper are given over real data from a 12700km length link from the Antarctica to Spain, transmitted on January and February 2008.