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Vector Approximate Message Passing Based OFDM-IM Detection for Underwater Acoustic Communications
Xiao Feng1,2, Feng Tian1,2, Mingzhang Zhou2,3
1School of Communication and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China.
Entropy (Basel, Switzerland)
|December 23, 2023
Summary
This study introduces a low-complexity Vector Approximate Message Passing (VAMP) detector for underwater acoustic Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) communications, enabling real-time data transmission.
Area of Science:
- Underwater Acoustic Communications
- Signal Processing
- Information Theory
Background:
- Orthogonal frequency division multiplexing with index modulation (OFDM-IM) offers high spectral efficiency for underwater acoustic (UWA) communications.
- Traditional maximum likelihood detection methods for OFDM-IM are computationally intensive, hindering real-time applications in UWA environments.
Purpose of the Study:
- To develop a computationally efficient and effective detection algorithm for UWA OFDM-IM systems.
- To enable real-time data transmission in challenging underwater acoustic environments.
Main Methods:
- A Vector Approximate Message Passing (VAMP) algorithm framework was formulated for index detection in OFDM-IM.
- A novel shrinkage function was derived using the minimum mean square error criterion, exploiting the inherent sparsity of OFDM-IM symbols.
- A lookup table-based Euclidean distance search was employed to correct erroneously estimated indices.
Main Results:
- The proposed VAMP-based detector demonstrates significantly lower computational complexity compared to existing methods.
- The detector exhibits improved robustness and effectiveness in UWA OFDM-IM communication scenarios.
- Experimental results validate the performance advantages of the VAMP detector.
Conclusions:
- The VAMP-based detection offers a viable solution for real-time, high spectral-efficiency UWA OFDM-IM communications.
- The proposed method overcomes the computational limitations of traditional detectors.
- This approach enhances the feasibility of advanced communication techniques in underwater environments.
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