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. 06, 2004
Filed:
May. 27, 1999
Yaqi Cheng, Rowlett, TX (US);
3Com Corporation, Santa Clara, CA (US);
Abstract
A method and apparatus for reducing peak-to-average power ratio in a discrete multi-tone signal. A shaping signal is generated and added to a discrete multi-tone signal to be transmitted. The shaping signal includes tones that are outside a transmission band assigned to the discrete multi-tone signal to be transmitted. One or more filters may be used to suppress the shaping function after digital-to-analog conversion has been performed. Alternatively, echo cancellation may be performed to cancel feedback tones associated with the transmit signal and shaping signal that may occur on the receive path of a discrete multi-tone transceiver. The peak-to-average power ratio reduction method and apparatus may be used in an ADSL modem in one embodiment.