L-3 Communications Corporation

Kyle L Henderson

Thomas R Giallorenzi

Johnny M Harris

Dan M Griffin

Eric K Hall

Lee A Butterfield

Michael J Hurst

Michael D Pulsipher

Marc J Russon

Kent M Erickson

An emergency locating system can include emergency transceivers and locator transceivers. The emergency transceivers can be capable of transmission of spread-spectrum encoded messages, and can be actuated by a user to send a distress message. A locator transceiver can be capable of receiving the distress messages and performing two-way ranging to determine a distance between the locator transceiver and the emergency transceiver.

Emergency locating system and method using spread-spectrum transceiver

A method is disclosed for operating a synchronous Code Division Multiple Access (S-CDMA) radio frequency communication system having a host transceiver unit and a plurality of user transceiver units. The method includes an initial step of defining a super-frame to be comprised of N sequential frames of data. In the preferred embodiment N is equal to three. For a user transceiver unit that obtains access to the host transceiver unit a next step of the method receives frames of data transmitted by the host transceiver unit and initially aligns a receiver timing and a transmitter timing of the user transceiver unit to a super-frame boundary of the received frames. A next step transmits frames of data from the user transceiver unit to the host transceiver unit using the initial timing alignment. A further step of the method detects at the host transceiver unit a difference between the arrival of the transmitted frames of data and a super-frame boundary and then transmits a timing correction parameter, preferably expressed in symbols, from the host transceiver unit to the user transceiver unit in order to align the transmitted frames of data to the super-frame boundary.

S-CDMA fixed wireless loop system employing subscriber unit/radio base

Growing community of inventors

Lehi, UT, United States of America

Kyle L Henderson