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Prefiltered Single-Carrier Frequency-Domain Equalization for Binary CPM over Shallow Water Acoustic Channel
Ruigang Han1,2,3, Ning Jia1,2,3, Zhongyuan Guo1,2,3
1Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
Sensors (Basel, Switzerland)
|May 28, 2022
Summary
A new prefiltered single-carrier frequency-domain equalization (PF-SCFDE) algorithm improves continuous phase modulation in underwater acoustic channels. This method enhances performance by incorporating forward information for maximum likelihood estimation, reducing bit error rates.
Area of Science:
- Electrical Engineering
- Signal Processing
- Ocean Engineering
Background:
- Continuous phase modulation (CPM) is suitable for limited bandwidth, high attenuation underwater acoustic (UWA) channels.
- Severe intersymbol interference (ISI) hinders CPM application in shallow water environments.
Purpose of the Study:
- To introduce a novel prefiltered single-carrier frequency-domain equalization (PF-SCFDE) algorithm.
- To mitigate intersymbol interference in UWA communication systems.
Main Methods:
- Replaced the conventional whitening filter with a prefilter to extract forward information.
- Employed maximum likelihood estimation using the equalizer output combined with forward information.
- Simulated performance using minimum-shift keying (MSK) and Gaussian-filtered MSK (GFMSK) signals.
Main Results:
- PF-SCFDE achieved approximately 1 dB improvement over traditional single-carrier frequency-domain equalization (SCFDE) at a bit error rate (BER) of 10-4.
- Shallow sea trials confirmed PF-SCFDE's effectiveness, showing an 18.35% BER reduction compared to SCFDE.
Conclusions:
- The proposed PF-SCFDE algorithm effectively combats intersymbol interference in shallow UWA channels.
- PF-SCFDE offers superior performance and practical viability for UWA communication systems.
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