| 摘要 |
A signal processing system of a multiplexed FBG sensor using CDMA includes a pseudo random bit sequences (PRBS) generator for generating pseudo random bit sequence; a LED for light-emitting at a pseudo random bit from the PRBS generator; a fiber coupler for transmitting a light signal from the LED into a FBG sensor portion and passing signals reflected by the FBG sensor portion herethrough; the FBG sensor portion for receiving/reflecting the light signal via an optic fiber to forward it back to the fiber coupler; an FBG filter portion for filtering the signal reflected by the FBG sensor portion and passed through the fiber coupler; photo detector for converting the light signal from the FBG filter portion into the electrical signal; a delaying portion for delaying a pseudo random bit signal from the PRBS generator for a predetermined time period; a mixing portion for mixing the delay signal from the 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, thereby enhancing the stability of the system and the linearity of a signal to be measured to applied strain.
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