Experimental study of efficient multi-band underwater acoustic communication algorithm

Abstract

In the underwater acoustic communication environment, multipath transfer characteristics or Doppler spread due to time and space changes such as seabed, sea level, and water depth affect the performance. The multi-band communication technique is effective in terms of performance and throughput efficiency because it can overcome selective frequency fading by allocating the same data to different frequency bands in the environment of rapidly changing channel transfer characteristic. In addition, the transmission distance can be further extended while overcoming various underwater channel environments. However, the multi-band configuration may have worse performance than the single-band one. It is because the performance degradation in a particular band affects the output from the entire bands, which is input into a decoder, thereby decreasing the overall performance. This problem can be solved through a receiving end that analyzes error rates of each band, sets threshold values, and allocates lower weights to inferior bands. In this paper, we proposed an algorithm to set the threshold value using the preamble error rate, which is known data to be transmitted and received. We have analyzed the efficiency of multi-band transmission scheme by applying 1–4 number of multi-bands using turbo pi code through actual underwater experiment.