Lear Siegler, Inc.

Gordon P Eckley

Ronald J Fredricks

Thomas E Perfitt

Jerry L Page

Harry L Gubbins

Wilbur A Carrington

A telephone communication system for transmitting and receiving both voice signals and digital data signals, with no significant distortion to the voice signals and with substantially higher digital data rates than previously could be obtained in comparable systems. The voice signals are digitized, data compressed, and time-division multiplexed with the digital data signals, to produce a composite digital signal that can be transmitted over conventional telephone lines. The system can be selectively configured in a conventional telephone operating mode, in which the system transmits and receives merely the analog voice signals and all of its various digital circuitry elements are bypassed. The system is automatically configured in this conventional telephone operating mode whenever a significant failure in any of its individual units is detected.

Voice and data communication system

An optical rate sensor (200) is disclosed for use in inertial reference systems to measure rates of angular rotation with substantially high resolution and sensitivity. The sensor (200) comprises a passive ring Sagnac interferometer (201) with a multiturn fiber optic ring (232) through which counter-propagating optical waves are transmitted. A nonreciprocal time variant phase modulation is applied to the waves along with periodic effective transposition of ring ports. The waves are combined to produce a 'zero order' fringe pattern having an intensity varying in accordance with the relative phase between the counter-propagating waves. An intensity signal is derived from the fringe pattern having a phase offset corresponding to the Sagnac induced phase shift which in turn is linearly proportional to the angular rotation rate of the passive ring. Sampling, averaging and estimation circuits detemine the offset by detecting zero-crossing locations of the signal.

Growing community of inventors

Grand Rapids, MI, United States of America

Gordon P Eckley