Patent ID: 6892031
Filing Date: 2005-05-10
Classification: G01D,G01L

Abstract:
1. A signal processing system of a multiplexed FBG sensor system with a plurality of FBG sensors using CDMA, the signal processing system comprising: a pseudo random bit sequence (PRBS) generator for generating pseudo random bit sequence connected to a LED for light-emitting at a pseudo random bit from the PRBS generator to generate light signals; a fiber coupler connected to the LED and for transmitting light signals from the LED into an FBG sensor portion and passing signals reflected by the FBG sensor portion therethrough; the FBG sensor portion including at least two FBG sensors for receiving launched light signals and reflecting them at different Bragg wavelengths via an optic fiber to forward it back to the fiber coupler, in which the FBG sensors have a wavelength different from each other; an FBG filter portion including at least two FBG filters which have a Bragg wavelength different from each other, which is connected to the fiber coupler, and for filtering the light signals reflected by the FBG sensor portion and passed through the fiber coupler, in which the FBG filter portion is constituted as fiber Bragg gratings at least two FBGs along with the fiber; and a photo detector for converting the light signal from the FBG filter portion into the electrical signal, at least one delaying portion for delaying a pseudo random bit signal from the PRBS generator for a predetermined time period, and a mixing portion for mixing the delay signal from the scanning delaying portion and the output signal from the photo detector and at least one auto-correlation device for integrating or auto-correlating the signal from the mixing portion.