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Bandwidth-efficient frequency-domain equalization for single carrier multiple-input multiple-output underwater
Jian Zhang1, Yahong Rosa Zheng
1Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, Missouri 65409, USA.
The Journal of the Acoustical Society of America
|November 30, 2010
Summary
This study introduces an overlapped-window frequency-domain equalization (FDE) for underwater acoustic (UWA) communications. This method enhances data efficiency and reduces bit error rates in UWA systems.
Area of Science:
- Electrical Engineering
- Ocean Engineering
- Signal Processing
Background:
- Underwater acoustic (UWA) communication systems face challenges with bandwidth efficiency and error performance.
- Traditional frequency-domain equalization (FDE) methods applied to entire data blocks can be inefficient for UWA channels.
- Existing UWA systems often require significant transmission overhead for reliable communication.
Purpose of the Study:
- To propose a novel single carrier (SC) receiver scheme with bandwidth-efficient frequency-domain equalization (FDE) for UWA communications.
- To improve data efficiency and reduce bit error rate (BER) in UWA systems using multiple transducers and hydrophones.
- To develop an overlapped-window FDE algorithm that tracks channel variations effectively.
Main Methods:
- Implementation of an overlapped-window FDE by partitioning data blocks into smaller subblocks.
- Integration of a decision-directed channel estimation scheme with the overlapped-window FDE.
- Testing the proposed scheme using undersea data from the Rescheduled Acoustic Communications Experiment (RACE).
Main Results:
- The 2-by-12 MIMO overlapped-window FDE significantly reduced average BER by 74.4% (400m) and 84.6% (1000m) compared to traditional SC-FDE.
- The proposed algorithm achieves better data efficiency by increasing block length while maintaining training symbol density.
- Required transmission overhead was reduced to 8.4%, substantially lower than over 20% in other UWA systems, for equivalent BER performance.
Conclusions:
- The proposed overlapped-window FDE scheme offers superior data efficiency and error performance for UWA communications.
- The method effectively tracks channel variations, leading to significant BER reduction without compromising data rates.
- This approach presents a viable solution for enhancing the reliability and efficiency of underwater acoustic communication systems.
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