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:
Jul. 29, 2008
Filed:
Oct. 09, 2003
Yi Zheng, Sartell, MN (US);
Aiping Yao, St. Cloud, MN (US);
Yi Zheng, Sartell, MN (US);
Aiping Yao, St. Cloud, MN (US);
Other;
Abstract
The present invention of the modulation and demondulation removes the carry synchronization requirement for spread spectrum systems and code-division multiple access communication systems. The invention uses the PN codes that are specially selected and asynchronous demodulation procedure. If number of transmitters is limited, the Multiple Access Interference (MAI) due to carry differences of transmitters can be completely cancelled. Using this invention, signal from a desired transmitter can be demodulated and detected from received signals included from other transmitters in multiple access applications, even when the frequencies of transmitters are different from each other and are not synchronized with a receiver. The invention greatly reduces complexities of a wireless system where Code Division Multiple Access (CDMA) or spread spectrum is used. It expands applications of wireless communication. One of the applications is for a CDMA communication for multiple users without a centralized base station.