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. 17, 2002
Filed:
Jun. 11, 1999
Mitigation of co-channel interference in synchronization bursts in a multi-beam communication system
Stuart T. Linsky, San Pedro, CA (US);
Gregory S. Caso, Hermosa Beach, CA (US);
David A. Wright, Solana Beach, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
In a cellular satellite system such as Astrolink, where same frequency, same polarization (same “color”) signals are used in multiple ground cells, there exists the possibility of interference and false reception of uplink Synchronization Bursts (SB) in systems employing TDMA access of the frequency in question. In such systems, a SB transmitted from one terminal may be received in more than one satellite beam. The reception of the signal from a terminal in an undesired beam ( ) is erroneous and may adversely impact the time synchronization ( ) of the desired terminal. For example, a system may employ Maximal Length (ML) Pseudo-Noise (PN) sequences ( ) for its SBs wherein every beam may use the same sequence. To minimize false reception, the ML PN sequences ( ) of each SB may be cyclicly shifted a different amount for each beam to generate sequences ( ) having low corsscorrelation with each other. By choosing ML PN codes having low crosscorrelation ( ) for the different beams, the interference from undesired beams may be minimized ( ).