%0 Journal Article %1 Seco-Granados2001 %A Seco-Granados, G. %A Fernandez-Rubio, J. A. %A Lee Swindlehurst, A. %D 2001 %J Signal Processing (Elsevier) %K GPS, ML, acquisition, estimation, satnav tracking antennas %P 1-22 %T Code-timing synchronization in DS-CDMA systems using space-time diversity %X The synchronization of a desired user transmitting a known training sequence in a direct-sequence (DS) asynchronous code-division multiple-access (CDMA) system is addressed. It is assumed that the receiver consists of an arbitrary antenna array and works in a near-far, frequency-nonselective, slowly fading channel. The estimator that we propose is derived by applying the maximum likelihood (ML) principle to a signal model in which the contribution of all the interfering components (e.g., multiple-access interference, external interference and noise) is modeled as a Gaussian term with an unknown and arbitrary space-time correlation matrix. The main contribution of this paper is the fact that the estimator makes efficient use of the structure of the signals in both the space and time domains. Its performance is compared with the Cramer-Rao Bound, and with the performance of other methods proposed recently that also employ an antenna array but only exploit the structure of the signals in one of the two domains, while using the other simply as a means of path diversity. It is shown that the use of the temporal and spatial structures is necessary to achieve synchronization in heavily loaded systems or in the presence of directional external interference.

@article{Seco-Granados2001, abstract = {The synchronization of a desired user transmitting a known training sequence in a direct-sequence (DS) asynchronous code-division multiple-access (CDMA) system is addressed. It is assumed that the receiver consists of an arbitrary antenna array and works in a near-far, frequency-nonselective, slowly fading channel. The estimator that we propose is derived by applying the maximum likelihood (ML) principle to a signal model in which the contribution of all the interfering components (e.g., multiple-access interference, external interference and noise) is modeled as a Gaussian term with an unknown and arbitrary space-time correlation matrix. The main contribution of this paper is the fact that the estimator makes efficient use of the structure of the signals in both the space and time domains. Its performance is compared with the Cramer-Rao Bound, and with the performance of other methods proposed recently that also employ an antenna array but only exploit the structure of the signals in one of the two domains, while using the other simply as a means of path diversity. It is shown that the use of the temporal and spatial structures is necessary to achieve synchronization in heavily loaded systems or in the presence of directional external interference.}, added-at = {2011-05-30T10:41:10.000+0200}, author = {{Seco-Granados}, G. and {Fernandez-Rubio}, J. A. and {Lee Swindlehurst}, A.}, biburl = {https://www.bibsonomy.org/bibtex/271ecf3538e764c6552973122461785b5/bmuth}, groups = {private}, interhash = {5cb037dc4944784ca245544c005fa8d2}, intrahash = {71ecf3538e764c6552973122461785b5}, journal = {Signal Processing (Elsevier)}, keywords = {GPS, ML, acquisition, estimation, satnav tracking antennas}, owner = {bmuth}, pages = {1-22}, timestamp = {2014-08-11T22:40:24.000+0200}, title = {{Code-timing synchronization in DS-CDMA systems using space-time diversity}}, username = {bmuth}, year = 2001 }