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:
Sep. 01, 2009
Filed:
Dec. 15, 2005
Ning Guo, Kanata, CA;
Neil Mcgowan, Stittsville, CA;
Gary Boudreau, Kanata, CA;
Nortel Networks Limited, St. Laurent, Quebec, CA;
Abstract
A method and apparatus for reducing the peak to average power ratio of an OFDM signal. The method involves operating on the signal only after it is converted to the time domain where the signal is compared to a power threshold and any signal above the power threshold is considered undesirable. A reduced signal is produced by reducing the magnitude to the power threshold whenever it exceeds that threshold. The delta between the original signal and reduced signal is the clipped signal. The clipped signal is multiplied by a g-function, and then subtracted from the original signal to produce a first iteration of a peak-reduced signal. The process can then be repeated using the first peak-reduced signal in place of the original signal to produce the second iteration of a peak-reduced signal. This process can be repeated each time bringing the peaks closer to the power threshold. The g-function can be defined either to allow for per-symbol cyclic signal processing or non-cyclic processing that is symbol time independent.