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. 27, 2009
Filed:
Jan. 17, 2003
Lin-nan Lee, Potomac, MD (US);
Khalid Karimullah, Olney, MD (US);
Feng-wen Sun, Germantown, MD (US);
Kamran Etemad, Gaithersburg, MD (US);
Lin-Nan Lee, Potomac, MD (US);
Khalid Karimullah, Olney, MD (US);
Feng-Wen Sun, Germantown, MD (US);
Kamran Etemad, Gaithersburg, MD (US);
The DIRECTV Group, Inc., El Segundo, CA (US);
Abstract
A communication system is used to transmit and receive data on a plurality of relatively narrow-band signals and wideband signals. The two signal types share a common electromagnetic spectrum by employing spreading gain and maintaining orthogonality between simultaneously transmitted wideband and narrow-band signals. Signal orthogonality is maintained by selectively choosing orthogonal codes and aligning or spacing a wideband carrier frequency with respect to the narrow-band carrier frequencies in accordance with the ratio of the wideband to the narrow-band chip frequencies. A pilot signal is preferably transmitted contemporaneously with the transmission of the first spread signal, and a control date signal, associated with a plurality of users on the first bandwidth, is transmitted on a common control channel using a single Walsh code that is shared by a plurality of users in a TDMA protocol.