- 标题
- 摘要
- 关键词
- 实验方案
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Programmable Photonics: An Opportunity for an Accessible Large-Volume PIC Ecosystem
摘要： Underwater acoustic (UWA) channels are characterized by a severe spread in time and frequency, and are usually labeled as “doubly spread channels.” In this paper, we propose Doppler-resilient orthogonal signal-division multiplexing (D–OSDM), to provide a highly reliable communication environment in doubly spread channels for UWA communication. D–OSDM multiplexes several data vectors in addition to a pilot vector, and preserves orthogonality among them even after propagation through doubly spread channels, under the assumption that the channel can be modeled by a basis expansion model (BEM). We describe the signal processing steps at the transmitter and the receiver for D–OSDM, and evaluate its performance by both simulations and experiments. To generate a doubly spread channel, a test tank with a wave generator is employed. The obtained results suggest that D–OSDM can provide low-power and high-quality UWA communications in channels with large delay and Doppler spreads; for example, D–OSDM succeeds to achieve a block error rate (BLER) of 10 while BEM-based orthogonal frequency-division multiplexing (OFDM) has a BLER ?oor of in the experiments. Equivalently, D–OSDM can reduce the 10 signal power required for communications to achieve the same BER signi?cantly. Overall, it was found that D–OSDM can become a powerful communication tool for underwater operations.
关键词： multipath channels,Doppler,underwater acoustic (UWA) communication
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A plasmonic bandpass filter based on meander-slotted substrate integrated waveguide
摘要： Time reversal (TR) exploits spatial diversity to achieve spatial and temporal focusing in complex environments. Over the last decade, the TR concept has been applied successfully to phase-coherent acoustic communications in time-varying multipath ocean environments, as an alternative to conventional adaptive multichannel equalization. Temporal focusing (pulse compression) mitigates the intersymbol interference (ISI) and subsequent single-channel equalization removes the residual ISI, thus providing nearly optimal performance in theory. The spatial focusing capability facilitates multiuser or multiple-input–multiple-output (MIMO) communications without explicit use of time, frequency, or code division multiplexing, while an adaptive TR approach can reduce further the crosstalk among users or multiple transmitters. TR communications can be extended easily to time-varying channels using a block-based approach with channel updates. This paper provides an overview of TR communications in both shallow and deep water and recent advances including bidirectional equalization, multiuser communications with mobile users, and communication with a glider serving as a mobile gateway.
关键词： time reversal (TR),underwater acoustic (UWA) communication,Adaptive multichannel equalization,MIMO/multiuser communication,crosstalk
更新于2025-09-23 15:19:57
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Design of a Multi-wavelength Fiber Laser Based on Tm:Er:Yb:Ho Co-doped Germanate Glass
摘要： Time reversal (TR) exploits spatial diversity to achieve spatial and temporal focusing in complex environments. Over the last decade, the TR concept has been applied successfully to phase-coherent acoustic communications in time-varying multipath ocean environments, as an alternative to conventional adaptive multichannel equalization. Temporal focusing (pulse compression) mitigates the intersymbol interference (ISI) and subsequent single-channel equalization removes the residual ISI, thus providing nearly optimal performance in theory. The spatial focusing capability facilitates multiuser or multiple-input–multiple-output (MIMO) communications without explicit use of time, frequency, or code division multiplexing, while an adaptive TR approach can reduce further the crosstalk among users or multiple transmitters. TR communications can be extended easily to time-varying channels using a block-based approach with channel updates. This paper provides an overview of TR communications in both shallow and deep water and recent advances including bidirectional equalization, multiuser communications with mobile users, and communication with a glider serving as a mobile gateway.
关键词： crosstalk,underwater acoustic (UWA) communication,Adaptive multichannel equalization,time reversal (TR),MIMO/multiuser communication
更新于2025-09-19 17:13:59
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[IEEE 2019 1st International Conference on Electrical, Control and Instrumentation Engineering (ICECIE) - Kuala Lumpur, Malaysia (2019.11.25-2019.11.25)] 2019 1st International Conference on Electrical, Control and Instrumentation Engineering (ICECIE) - Development of RGB LED Based Compact Multipurpose Colorimeter for Hemoglobin Estimation of Blood
摘要： Time reversal (TR) exploits spatial diversity to achieve spatial and temporal focusing in complex environments. Over the last decade, the TR concept has been applied successfully to phase-coherent acoustic communications in time-varying multipath ocean environments, as an alternative to conventional adaptive multichannel equalization. Temporal focusing (pulse compression) mitigates the intersymbol interference (ISI) and subsequent single-channel equalization removes the residual ISI, thus providing nearly optimal performance in theory. The spatial focusing capability facilitates multiuser or multiple-input–multiple-output (MIMO) communications without explicit use of time, frequency, or code division multiplexing, while an adaptive TR approach can reduce further the crosstalk among users or multiple transmitters. TR communications can be extended easily to time-varying channels using a block-based approach with channel updates. This paper provides an overview of TR communications in both shallow and deep water and recent advances including bidirectional equalization, multiuser communications with mobile users, and communication with a glider serving as a mobile gateway.
关键词： time reversal (TR),underwater acoustic (UWA) communication,Adaptive multichannel equalization,MIMO/multiuser communication,crosstalk
更新于2025-09-19 17:13:59
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[IEEE 2019 2nd International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT) - Kannur,Kerala, India (2019.7.5-2019.7.6)] 2019 2nd International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT) - Calibration of an optical sensor for in vivo blood glucose maeasurenaent
摘要： Underwater acoustic (UWA) channels are characterized by a severe spread in time and frequency, and are usually labeled as “doubly spread channels.” In this paper, we propose Doppler-resilient orthogonal signal-division multiplexing (D–OSDM), to provide a highly reliable communication environment in doubly spread channels for UWA communication. D–OSDM multiplexes several data vectors in addition to a pilot vector, and preserves orthogonality among them even after propagation through doubly spread channels, under the assumption that the channel can be modeled by a basis expansion model (BEM). We describe the signal processing steps at the transmitter and the receiver for D–OSDM, and evaluate its performance by both simulations and experiments. To generate a doubly spread channel, a test tank with a wave generator is employed. The obtained results suggest that D–OSDM can provide low-power and high-quality UWA communications in channels with large delay and Doppler spreads; for example, D–OSDM succeeds to achieve a block error rate (BLER) of 10 while BEM-based orthogonal frequency-division multiplexing (OFDM) has a BLER ?oor of in the experiments. Equivalently, D–OSDM can reduce the 10 signal power required for communications to achieve the same BER signi?cantly. Overall, it was found that D–OSDM can become a powerful communication tool for underwater operations.
关键词： multipath channels,Doppler,underwater acoustic (UWA) communication
更新于2025-09-19 17:13:59
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[IEEE 2019 Device Research Conference (DRC) - Ann Arbor, MI, USA (2019.6.23-2019.6.26)] 2019 Device Research Conference (DRC) - WSe <sub/>2</sub> based Valley-Coupled-Spintronic Devices for Low Power Non-Volatile Memories
摘要： Underwater acoustic (UWA) channels are characterized by a severe spread in time and frequency, and are usually labeled as “doubly spread channels.” In this paper, we propose Doppler-resilient orthogonal signal-division multiplexing (D–OSDM), to provide a highly reliable communication environment in doubly spread channels for UWA communication. D–OSDM multiplexes several data vectors in addition to a pilot vector, and preserves orthogonality among them even after propagation through doubly spread channels, under the assumption that the channel can be modeled by a basis expansion model (BEM). We describe the signal processing steps at the transmitter and the receiver for D–OSDM, and evaluate its performance by both simulations and experiments. To generate a doubly spread channel, a test tank with a wave generator is employed. The obtained results suggest that D–OSDM can provide low-power and high-quality UWA communications in channels with large delay and Doppler spreads; for example, D–OSDM succeeds to achieve a block error rate (BLER) of 10 while BEM-based orthogonal frequency-division multiplexing (OFDM) has a BLER ?oor of in the experiments. Equivalently, D–OSDM can reduce the 10 signal power required for communications to achieve the same BER signi?cantly. Overall, it was found that D–OSDM can become a powerful communication tool for underwater operations.
关键词： underwater acoustic (UWA) communication,multipath channels,Doppler
更新于2025-09-19 17:13:59