The Chaotic Baseband Wireless Communication System(CBWCS)is expected to eliminate the Inter-Symbol Interference(ISI)caused by multipath propagation by using the optimal decoding threshold that is the sum of the ISI ca...The Chaotic Baseband Wireless Communication System(CBWCS)is expected to eliminate the Inter-Symbol Interference(ISI)caused by multipath propagation by using the optimal decoding threshold that is the sum of the ISI caused by past decoded bits and the ISI caused by future transmitting bits.However,the current technique is only capable of removing partial effects of the ISI,because only past decoded bits are available for the suboptimal decoding threshold calculation.The unavailability of the future information needed for the optimal decoding threshold is an obstacle to further improve the Bit Error Rate(BER)performance.In contrast to the previous method using Echo State Network(ESN)to predict one future bit,the proposed method in this paper predicts the optimal decoding threshold directly using ESN.The proposed ESN-based threshold prediction method simplifies the symbol decoding operation by avoiding the iterative prediction of the output waveform points using ESN and accumulated error caused by the iterative operation.With this approach,the calculation complexity is reduced compared to the previous ESN-based approach.The proposed method achieves better BER performance compared to the previous method.The reason for this superior result is twofold.First,the proposed ESN is capable of using more future symbols information conveyed by the ESN input to obtain more accurate threshold rather than the previous method in which only one future symbol was available.Second,the proposed method here does not need to estimate the channel information using Least Squared(LS)method,which avoids the extra error caused by inaccurate channel information estimation.Simulation results and experiment based on a wireless open-access research platform under a practical wireless channel show the effectiveness and superiority of the proposed method.展开更多
By employing a rational approach,we prepared a novel kind of luminescent europium-centered hybrid material named Eu(tta)_(3)NCP-TiO_(2).The resulting material was characterized by FT-IR spectra,SEM,X-ray diffraction,t...By employing a rational approach,we prepared a novel kind of luminescent europium-centered hybrid material named Eu(tta)_(3)NCP-TiO_(2).The resulting material was characterized by FT-IR spectra,SEM,X-ray diffraction,thermogravimetric analysis,and photoluminescence spectra.The hybrid material features the combined advantages of the europium complex and the titania host,exhibiting not only good thermostability,but also long luminescence lifetime.Owing to the excellent luminescence of this material,the application in detecting organic small molecule solvents and metal ions was explored systematically.Significantly,Eu(tta)_(3)NCP-TiO_(2) exhibits superior detection for nitrobenzene molecule and Cu^(2+) ion in DMF(N,N-dimethylformamide) medium.Furthermore,the limit of detection(LOD) of Eu(tta)_(3)NCP-TiO_(2) for nitrobenzene and Cu^(2+) ion can be counted as 5.593× 10^(-5) and 9.566 ×10^(-5) mol/L,respectively.The results demonstrate that Eu(tta)_(3)NCP-TiO_(2) can serve as an efficient fluorescence probe for the detection of sensing of nitrobenzene and Cu^(2+) ion.展开更多
文摘The Chaotic Baseband Wireless Communication System(CBWCS)is expected to eliminate the Inter-Symbol Interference(ISI)caused by multipath propagation by using the optimal decoding threshold that is the sum of the ISI caused by past decoded bits and the ISI caused by future transmitting bits.However,the current technique is only capable of removing partial effects of the ISI,because only past decoded bits are available for the suboptimal decoding threshold calculation.The unavailability of the future information needed for the optimal decoding threshold is an obstacle to further improve the Bit Error Rate(BER)performance.In contrast to the previous method using Echo State Network(ESN)to predict one future bit,the proposed method in this paper predicts the optimal decoding threshold directly using ESN.The proposed ESN-based threshold prediction method simplifies the symbol decoding operation by avoiding the iterative prediction of the output waveform points using ESN and accumulated error caused by the iterative operation.With this approach,the calculation complexity is reduced compared to the previous ESN-based approach.The proposed method achieves better BER performance compared to the previous method.The reason for this superior result is twofold.First,the proposed ESN is capable of using more future symbols information conveyed by the ESN input to obtain more accurate threshold rather than the previous method in which only one future symbol was available.Second,the proposed method here does not need to estimate the channel information using Least Squared(LS)method,which avoids the extra error caused by inaccurate channel information estimation.Simulation results and experiment based on a wireless open-access research platform under a practical wireless channel show the effectiveness and superiority of the proposed method.
基金Project supported by the National Natural Science Foundation of China(21473133,21173164)。
文摘By employing a rational approach,we prepared a novel kind of luminescent europium-centered hybrid material named Eu(tta)_(3)NCP-TiO_(2).The resulting material was characterized by FT-IR spectra,SEM,X-ray diffraction,thermogravimetric analysis,and photoluminescence spectra.The hybrid material features the combined advantages of the europium complex and the titania host,exhibiting not only good thermostability,but also long luminescence lifetime.Owing to the excellent luminescence of this material,the application in detecting organic small molecule solvents and metal ions was explored systematically.Significantly,Eu(tta)_(3)NCP-TiO_(2) exhibits superior detection for nitrobenzene molecule and Cu^(2+) ion in DMF(N,N-dimethylformamide) medium.Furthermore,the limit of detection(LOD) of Eu(tta)_(3)NCP-TiO_(2) for nitrobenzene and Cu^(2+) ion can be counted as 5.593× 10^(-5) and 9.566 ×10^(-5) mol/L,respectively.The results demonstrate that Eu(tta)_(3)NCP-TiO_(2) can serve as an efficient fluorescence probe for the detection of sensing of nitrobenzene and Cu^(2+) ion.
