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:
Feb. 09, 1999
Filed:
Jun. 17, 1996
John L Moran, III, Millville, MA (US);
Sanjeev Verma, Arlington, MA (US);
William Leslie Brown, Mississauga, CA;
Motorola, Inc., Schaumburg, IL (US);
Abstract
An apparatus, software modem, and method for a data communications device, such as a modem (100, 101), to determine a symbol rate and carrier frequency, from a received probe signal, for optimizing a bit rate for data transmission and reception. The various embodiments utilizing a processor (108) or a digital signal processor (106) receive a probe signal, which also typically contains noise and other distortions, particularly envelope delay distortion. The various method and apparatus embodiments then determine a variance of the envelope delay distortion, either directly or indirectly as a correlate of attenuation distortion or as a correlate of a selected transmit pre-emphasis filter specified under the ITU V.34 protocol. The variance of the envelope delay distortion is then utilized to eliminate or disable certain symbol rates and corresponding carrier frequencies in the determination of an optimal symbol rate and carrier frequency for data transmission and reception.