Data transfer using the low frequency longitudinal guided wave in a liquid-filled pipe

Guided wave mode selection for data transfer along a liquid-filled pipe is analyzed in detail on the basis of the propagation properties of the guided waves in the pipe. The combination of frequency hopping spread spectrum and Turbo code is adopted to overcome the multipath interference with long time delay of the liquid-filled pipe channel. A Turbo coded frequency hopping data transfer system using the guided wave in the liquid-filled pipe is constructed. Experimental results indicate that the data transfer rate of the system can reach 250 bit/s and its bit error rate (BER) can be lower than 10−5 if the signal-to-noise ratio (SNR) of the received signal is greater than 6 dB.