This paper proposes to use Fast Fourier Transform （ FFT ） / Inverse Fast Fourier Transform （IFFT）, instead of vector-matrix multiplication, to implement the spreading/despreoding in Carrier-Interferometry Orthogon...This paper proposes to use Fast Fourier Transform （ FFT ） / Inverse Fast Fourier Transform （IFFT）, instead of vector-matrix multiplication, to implement the spreading/despreoding in Carrier-Interferometry Orthogonal Frequency Division Multiplexing （ CI/OFDM） and Pseudo-Orthogonal Carrier lnterferometry OFDM （PO-CI/OFDM）. That can improve the signal processing efficiency of CI/OFDM and PO-CI/OFDM systems by about 2N/log2N and 2N/（ 1 ＋ log2 N） times respectively and dose not make any difference to the system function and performance. Moreover, the effi- ciency benefits will increase with the increase of the number of sub-carriers. In addition to that, we point out that the transmitter of CI/OFDM is actually technically equivalent to that of a single-carrier system with cyclic-prefix and the receiver of CI/OFDM is a typical OFDM receiver with CI despreading. Hence the low Peak-to-Average Power Ratio （PA- PR） property and high anti-fading performance of CI/OFDM system can be well explained .展开更多
To study the detection method of trimethyltin chloride in urine.Extraction trimethyltin chloride in urine by ethyl acetate,and detection by capillary gas chromatography and mass spectrometry method (GC-MS).The linear ...To study the detection method of trimethyltin chloride in urine.Extraction trimethyltin chloride in urine by ethyl acetate,and detection by capillary gas chromatography and mass spectrometry method (GC-MS).The linear range of trimethyltin chloride in the method was 0.776-19.4 μg/mL,the correlation coefficient was 0.999 9,the lowest detection concentration was 0.01 mg/L.Relative standard deviation(RSD) was 4.4%-8.6%,the recovery rates were 99.0%-110.0%,sample could be save in -20℃ at least one half year.The method was applicable to detect trimethyltin chloride in urine.展开更多
基金Paper supported by the Teaching and Research Award Programfor Outstanding Young Professor in High Education Institute, MOE,P.R.C.
文摘This paper proposes to use Fast Fourier Transform （ FFT ） / Inverse Fast Fourier Transform （IFFT）, instead of vector-matrix multiplication, to implement the spreading/despreoding in Carrier-Interferometry Orthogonal Frequency Division Multiplexing （ CI/OFDM） and Pseudo-Orthogonal Carrier lnterferometry OFDM （PO-CI/OFDM）. That can improve the signal processing efficiency of CI/OFDM and PO-CI/OFDM systems by about 2N/log2N and 2N/（ 1 ＋ log2 N） times respectively and dose not make any difference to the system function and performance. Moreover, the effi- ciency benefits will increase with the increase of the number of sub-carriers. In addition to that, we point out that the transmitter of CI/OFDM is actually technically equivalent to that of a single-carrier system with cyclic-prefix and the receiver of CI/OFDM is a typical OFDM receiver with CI despreading. Hence the low Peak-to-Average Power Ratio （PA- PR） property and high anti-fading performance of CI/OFDM system can be well explained .
文摘To study the detection method of trimethyltin chloride in urine.Extraction trimethyltin chloride in urine by ethyl acetate,and detection by capillary gas chromatography and mass spectrometry method (GC-MS).The linear range of trimethyltin chloride in the method was 0.776-19.4 μg/mL,the correlation coefficient was 0.999 9,the lowest detection concentration was 0.01 mg/L.Relative standard deviation(RSD) was 4.4%-8.6%,the recovery rates were 99.0%-110.0%,sample could be save in -20℃ at least one half year.The method was applicable to detect trimethyltin chloride in urine.
