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. 02, 2006
Filed:
Oct. 01, 2002
Qinfang Sun, Cupertino, CA (US);
Won-joon Choi, San Jose, CA (US);
Jeffrey M. Gilbert, Sunnyvale, CA (US);
Ning Zhang, Milpitas, CA (US);
Yi-hsiu Wang, Palo Alto, CA (US);
Tao-fei Samuel NG, Fremont, CA (US);
Qinfang Sun, Cupertino, CA (US);
Won-Joon Choi, San Jose, CA (US);
Jeffrey M. Gilbert, Sunnyvale, CA (US);
Ning Zhang, Milpitas, CA (US);
Yi-Hsiu Wang, Palo Alto, CA (US);
Tao-Fei Samuel Ng, Fremont, CA (US);
Atheros Communications, Inc., Santa Clara, CA (US);
Abstract
Current OFDM systems use a limited number of symbols and/or sub-channels to provide approximations for channel estimations and pilot tracking, i.e. phase estimations. For example, two training symbols in the preamble of a data packet are used to provide channel estimation. Four of the fifty-four sub-channels are reserved for providing phase estimation. However, noise and other imperfections can cause errors in both of these estimations, thereby degrading system performance. Advantageously, decision feedback mechanisms can be provided to significantly improve channel estimation and pilot tracking in OFDM systems. The decision feedback mechanisms can use data symbols in the data packet to improve channel estimation as well as data sub-channels to improve pilot tracking.