The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 2005
Filed:
Jan. 12, 1998
Essam Sourour, Raleigh, NC (US);
Greg Bottomley, Cary, NC (US);
Rajaram Ramesh, Cary, NC (US);
Sandeep Chennakeshu, Cary, NC (US);
Essam Sourour, Raleigh, NC (US);
Greg Bottomley, Cary, NC (US);
Rajaram Ramesh, Cary, NC (US);
Sandeep Chennakeshu, Cary, NC (US);
Ericsson, Inc., Research Triangle Park, NC (US);
Abstract
Multipath delay estimation of a direct sequence spread spectrum (DS-SS) signal transmitted in a multipath fading channel is accomplished by measuring the envelope of the signal to determine a new delay estimate. Delay estimates are also obtained in ray strength order, by subtracting out the influence of the stronger rays on the weaker ones. This subtraction approach can be performed iteratively, allowing further refinement of the delay estimates. Delay estimates can also be determined by minimizing the mean square error (MSE) between a measured correlation function and a modeled correlation function. The minimum mean square error (MMSE) approach can performed iteratively, to further refine the delay estimates. Maximum likelihood (ML) delay estimates can also be obtained by exploiting side information regarding the transmit and receive pulse shapes.