Low-complexity, low-power communications over a highly frequency-selective channel

Abstract

Recent studies have demonstrated the idea of transferring power and data through solid and metallic barriers using acoustic waves. This thesis considers data transmission along a structure such as a steel pipe. These channels exhibit strong multipath effects which cause the channel to be highly frequency-selective. Some existing techniques to overcome the frequency-selective fading require complex structures with high power consumption, making them poorly suited for some applications with extreme environmental conditions. This thesis presents a low-complexity, low-power communication system for these frequency-selective channels. A double-carrier binary phase-shift keying with direct-sequence spread spectrum modulation is presented along with several simple, non-coherent demodulation schemes. A simplified version of the modulation, binary on-off phase-shift keying with direct-sequence spread spectrum is also discussed. The performance of these modulations and detectors is analyzed and compared. Monte Carlo simulation results are used to validate the analysis and extend the evaluation to measured channel responses. Finally, practical experimental results are presented that verify the feasibility of communications through a steel pipe acoustic-electric channel.