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:
Aug. 01, 2006
Filed:
Mar. 29, 2002
Applicant:
John E Hudson, Stansted, GB;
Inventor:
John E Hudson, Stansted, GB;
Assignee:
Nortel Networks Limited, St. Laurent, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 27/30 (2006.01);
U.S. Cl.
CPC ...
Abstract
The use of cyclic prefixes with OFDM transmissions is known. Typically the prefix length is chosen to be at least as long as the duration of significant multipath in the transmission channel. However, OFDM has disadvantages in terms of DSP load and transmitter power amplifier specifications. The use of a cyclic prefix with periodic CDMA codes has been found to yield equivalent performance in terms of orthogonality in a dispersive channel and yet overcomes the disadvantages of cyclicly prefixed OFDM transmissions. Examples are given of Walsh Hadamard binary periodic codes.