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:
Mar. 15, 2011
Filed:
Apr. 30, 2004
Joshua Lawrence Koslov, Hopewell, NJ (US);
Kumar Ramaswamy, Princeton, NJ (US);
Joshua Lawrence Koslov, Hopewell, NJ (US);
Kumar Ramaswamy, Princeton, NJ (US);
Thomson Licensing, Boulogne, Billancourt, FR;
Abstract
A satellite communications system comprises a transmitter, a satellite transponder and a receiver. The transmitter transmits an uplink multi-level modulated signal (hierarchical modulation, layered modulation, etc.) to the satellite transponder, which broadcasts the multi-level modulated signal downlink to one, or more, receivers. The multi-level modulated signal comprises an upper layer and a lower layer. The lower layer conveys LDPC blocks, or LDPC frames, each LDPC block comprising S bits of data including a header portion and a data-bearing portion. The upper layer conveys shorter blocks, each shorter block comprising R bits of data, where R<S, the shorter block also comprising a header portion and a data-bearing portion. The transmitter synchronizes the start of transmission of each LDPC block to the start of transmission of a shorter block. The receiver uses the received shorter blocks to assist in searching for particular data in the lower layer portion of the received multi-level modulated signal. In particular, the receiver searches for synchronization data in the lower layer portion of the received signal upon detection of the header portion in a received shorter block.