An adaptive channel estimation algorithm for the channel length is proposed to construct a channel estimation model suitable for orthogonal frequency division multiplexing(OFDM)underwater acoustic communication signal...An adaptive channel estimation algorithm for the channel length is proposed to construct a channel estimation model suitable for orthogonal frequency division multiplexing(OFDM)underwater acoustic communication signals for the dependence of traditional channel estimation algorithms on channel length information.This algorithm can be adopted to evaluate channel estimation quality in real time and to adaptively adjust the channel length of the channel estimation algorithm according to the evaluation result,which satisfies the need of accurate estimation of unknown underwater acoustic channels and communication application;based on the study on the relationship between the OFDM communication bit error rate and the subcarrier signal to noise ratio,a self-adjusting optimization scheme for OFDM subcarrier transmitting power is proposed,which realizes underwater communication with the low bit error rate through higher energy efficiency.The validity of the research content is verified through simulation and field experiments.展开更多
This paper proposes a polarization multiplexed interrogation technique for fiber Bragg grating （FBG） sensor array. The novelty of the proposed model is its ability to reduce interference and cross talk, thus allowin...This paper proposes a polarization multiplexed interrogation technique for fiber Bragg grating （FBG） sensor array. The novelty of the proposed model is its ability to reduce interference and cross talk, thus allowing larger number of FBG sensors to be interrogated in an array. The calibration technique has been illustrated in this work for the FBG sensor array, where data from each sensor are linearly polarized and multiplexed before co-propagation, to find out the tapping points that enable identification of each sensor data uniquely. Simulation has been carried out for odd number and even number of sensors in an array. Even with interfering input, this proposed scheme can interrogate and distinctively identify each sensor data using appropriate tuning of polarization-splitter, polarization-rotator, and polarization-attenuator at the detector end during the calibration process. The significance of the proposed method is its compact size, which makes this calibration system ready to be deployed in real-time sensing applications and data acquisition from the FBG sensor array.展开更多
基金supported by the National Natural Science Foundation of China(51679247)
文摘An adaptive channel estimation algorithm for the channel length is proposed to construct a channel estimation model suitable for orthogonal frequency division multiplexing(OFDM)underwater acoustic communication signals for the dependence of traditional channel estimation algorithms on channel length information.This algorithm can be adopted to evaluate channel estimation quality in real time and to adaptively adjust the channel length of the channel estimation algorithm according to the evaluation result,which satisfies the need of accurate estimation of unknown underwater acoustic channels and communication application;based on the study on the relationship between the OFDM communication bit error rate and the subcarrier signal to noise ratio,a self-adjusting optimization scheme for OFDM subcarrier transmitting power is proposed,which realizes underwater communication with the low bit error rate through higher energy efficiency.The validity of the research content is verified through simulation and field experiments.
文摘This paper proposes a polarization multiplexed interrogation technique for fiber Bragg grating （FBG） sensor array. The novelty of the proposed model is its ability to reduce interference and cross talk, thus allowing larger number of FBG sensors to be interrogated in an array. The calibration technique has been illustrated in this work for the FBG sensor array, where data from each sensor are linearly polarized and multiplexed before co-propagation, to find out the tapping points that enable identification of each sensor data uniquely. Simulation has been carried out for odd number and even number of sensors in an array. Even with interfering input, this proposed scheme can interrogate and distinctively identify each sensor data using appropriate tuning of polarization-splitter, polarization-rotator, and polarization-attenuator at the detector end during the calibration process. The significance of the proposed method is its compact size, which makes this calibration system ready to be deployed in real-time sensing applications and data acquisition from the FBG sensor array.
