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:
May. 29, 2007
Filed:
Jul. 25, 2003
Kaushik Barman, Andhra Pradesh, IN;
Vellenki Umapathy Reddy, Andhra Pradesh, IN;
Kaushik Barman, Andhra Pradesh, IN;
Vellenki Umapathy Reddy, Andhra Pradesh, IN;
Hellosoft, Inc., San José, CA (US);
Abstract
The present invention provides a method and system for clock and carrier recovery in a direct sequence spread spectrum communication system. The process involves the receiver receiving a digital signal that has been transmitted by a remote transmitter. The method for joint clock and carrier recovery comprises the following steps. The received signal is down-converted and the signal is then converted to digital form. The signal is de-spread to obtain the phase of the signal constellation. The clock error at the receiver is then estimated from the phase error of the signal constellation by means of an optimal linear estimator. The discrete carrier frequency offset of the received signal is then estimated from the estimated clock error. The optimal linear estimator used here for estimating the clock error is also the maximum likelihood estimator.