Low Complexity Iterative Receiver Structure for Time Varying Frequency Selective Shallow Underwater Acoustic Channels using BICM-ID: Design and Experimental Results (2011)

Author(s): Shah CP, Tsimenidis CC, Sharif BS, Neasham JA

    Abstract: A single element receiver for short range shallow water communication is proposedas an alternative to costly beamformer structures by utilizing state of the art iterative demodula-tion techniques. The proposed receiver structure employs an adaptive decision feedback equalizer(DFE) and bit interleaved coded modulation with iterative decoding (BICM-ID) in conjunctionwith adaptive Doppler compensation. The performance of the proposed receiver is compared withan iterative receiver employing turbo BICM and a non-iterative receiver employing a Reed Solomon(RS) code. Experimental results show that the performance of a coding scheme strongly dependson the ability of the adaptive DFE to equalize the time varying channel. It is also shown thatunder severe channel conditions the RS code, which is capable of correcting burst errors, fails togive acceptable performance even in the case where perfect decisions were fed back into the DFE.It is, therefore, established that the BICM based receivers, i.e. turbo BICM and convolutionalBICM-ID, outperform the non-BICM receiver. Furthermore, it has been established that thereexists a fundamental trade-o® between the Doppler correction factor and the receiver performance.In practice, a large Doppler correction factor is required to compensate for severe Doppler e®ects,however, it leads to noise enhancement into the system. The critical result is that although theproposed convolutional BICM-ID receiver matches approximately the performance of turbo BICM,it exhibits lower implementation complexity and reduced memory requirements, attributes that areattractive for robust high data-rate underwater acoustic modems.

      • Date: 16-06-2011
      • Journal: IEEE Journal of Oceanic Engineering
      • Volume: 36
      • Issue: 3
      • Pages: 406-421
      • Publisher: IEEE
      • Publication type: Article
      • Bibliographic status: Published

      Jeffrey Neasham
      Senior Lecturer

      Professor Bayan Sharif
      Senior Research Investigator

      Dr Charalampos Tsimenidis
      Senior Lecturer