Abstract: An apparatus for communicating information over a pressurized fluid-carrying pipe connecting a plurality of serial nodes. A sounder node (i.e., transmitter) creates variable pressure patterns within the fluid-carrying pipe, which pressure patterns are identified and detected by other nodes. The patterns convey information or solicit responses from the receiving nodes. The receiving nodes reply to the pressure fluctuations by inducing reply pressure fluctuations in the fluid-carrying pipe or by communicating with the sounder node via a separate radio frequency communications system. The apparatus and method can be used as an information-carrying communications medium or a train linking methodology for a railroad train.

Abstract: An adaptive infinite impulse response (IIR) filter compensates for dispersive distortion in a fiber optic channel. The weighting coefficients of the IIR filter are updated in accordance with an error signal obtained by differentially combining the output of the IIR filter with downstream decision values or with an undistorted training signal. Undistorted training signals may be derived from training patterns (e.g., preamble) expressly transmitted for the purpose by the upstream transmitter, or from non-training, but known or predictable patterns transmitted by the upstream transmitter.

Abstract: An adaptive system composed of an adjustable inverse distortion operator or structure compensates for dispersive distortion in a fiber optic channel. Parameters of the inverse distortion operator are automatically estimated and updated in accordance with minimizing some cost function of an error signal obtained by differentially combining the output of the inverse distortion operator with downstream decision values or with an undistorted training signal. Undistorted training signals may be derived from bit patterns (e.g., preamble) expressly transmitted for the purpose of adjusting the compensation system or from other non-training patterns known to be embedded in the received signal from the transmitter.

Abstract: An apparatus for communicating information over a pressurized fluid-carrying pipe connecting a plurality of serial nodes. A sounder node (i.e., transmitter) creates variable pressure patterns within the fluid-carrying pipe, which pressure patterns are identified and detected by other nodes. The patterns convey information or solicit responses from the receiving nodes. The receiving nodes reply to the pressure fluctuations by inducing reply pressure fluctuations in the fluid-carrying pipe or by communicating with the sounder node via a separate radio frequency communications system. The apparatus and method can be used as an information-carrying communications medium or a train linking methodology for a railroad train.