Position enhanced communication system including system for embedding CDMA navigation beacons under the communications signals of a wireless communication system
Patent 5604765 Issued on February 18, 1997. Estimated Expiration Date: 
December 23, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 23, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesQuantized hyperbolic and inverse hyperbolic object location system Cellular telephone system that uses position of a mobile unit to make call management decisions Patent #: 5235633 InventorsAssigneeApplicationNo. 363773 filed on 12/23/1994US Classes:375/141, End-to-end transmission system340/825.49, Location indication370/311, Signaling for performing battery saving370/527, Superimposed or modulated on principal information375/335, More than two frequencies377/63, Charge-coupled device455/456.1Location monitoringExaminersPrimary: Chin, StephenAssistant: Vo, Don N. Attorney, Agent or FirmInternational ClassesH04B 015/00H04K 001/00 H04L 027/30 AbstractA cellular telephone system having three or more cell sites with each cell site having a source of cellular communication signals and an RF transmitter and antenna for broadcasting the cellular communication signals. A direct sequence spread spectrum waveform carrying navigation signals is embedded in the cellular communication signals, including controlling the signal strength of the navigation signals so that the combined energy of the navigation signals from all cell sites at any location is at least a predetermined energy level below the energy level of the cellular communication signals. Each cell site includes timing for timing the operation of a GPS receiver. An RF signpost system comprising a plurality of low powered RF broadcast stations, one each at a plurality of scattered geographic locations, each low powered RF broadcast station broadcasting a direct sequence spread spectrum digital RF waveform and a modulator to modulate the digital RF waveform with location information identifying the geographic locations, respectively. | |
