滤波器组多载波(Filter Bank Multi-Carrier,FBMC)是5G移动通信系统中可能替代OFDM的调制方式,但是其峰均比(Peak to Average Power Ratio,PAPR)较高。DFT扩频技术利用DFT扩展输入信号,将FBMC信号的PAPR降到单载波传输的水平,但是仍存...滤波器组多载波(Filter Bank Multi-Carrier,FBMC)是5G移动通信系统中可能替代OFDM的调制方式,但是其峰均比(Peak to Average Power Ratio,PAPR)较高。DFT扩频技术利用DFT扩展输入信号,将FBMC信号的PAPR降到单载波传输的水平,但是仍存在缺点:经过推导发现,在同一符号周期内,传输符号x(t)中有4种不同的符号,导致PAPR值较高。因此,对DFT扩频技术中的相移项进行改进,提出了一种基于多载波等时移条件的DFT扩频(Identically Time Shifted Multicarrier-DFT spreading,ITSM-DFTs)算法。该算法充分利用了DFT扩频技术的单载波效应,理论分析和仿真结果表明,该算法有效降低了FBMC系统的PAPR。展开更多
In this paper, an Ethernet controller SoC solution and its low power design for testability （DFT） for information appliances are presented. On a single chip, an enhanced one-cycle 8-bit micro controller unit （MCU）...In this paper, an Ethernet controller SoC solution and its low power design for testability （DFT） for information appliances are presented. On a single chip, an enhanced one-cycle 8-bit micro controller unit （MCU）, media access control （MAC） circuit and embedded memories such as static random access memory （SRAM）, read only memory （ROM） and flash are all integrated together. In order to achieve high fault coverage, at the same time with low test power, different DFT techniques are adopted for different circuits： the scan circuit that reduces switching activity is implemented for digital logic circuits; BIST-based method is employed for the on-chip SRAM and ROM. According to the fault-modeling of embedded flash, we resort to a March-like method for flash built in self test （BIST）. By all means above, the result shows that the fault coverage may reach 97%, and the SoC chip is implemented successfully by using 0.25 μm two-poly four-metal mixed signal complementary metal oxide semiconductor （CMOS） technology, the die area is 4.8×4.6 mm^2. Test results show that the maximum throughput of Ethemet packets may reach 7Mb·s^1.展开更多
Quantum chemical calculations have been carried out to investigate the vibrational frequencies of clonazepam. The FTIR spectrum of clonazepam was recorded in the region 4000 to 400 cm–1 in the solid phase. The optimi...Quantum chemical calculations have been carried out to investigate the vibrational frequencies of clonazepam. The FTIR spectrum of clonazepam was recorded in the region 4000 to 400 cm–1 in the solid phase. The optimized geometry, wave number and intensity of the vibrational bands of clonazepam were obtained by ab initio Restricted Hartree Fock (RHF) and Density Functional Theory (DFT) methods with complete relaxation in the potential energy surface using the 6-31G (d,p) basis set. A complete vibrational assignment aided by the theoretical harmonic frequency analysis is proposed. The observed and the calculated wavenumbers are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretical spectra. Theoretical spectrograms for the IR spectrum were also constructed in RHF and B3LYP levels. In addition to this the RHF and DFT based NMR calculation procedure was used to assign the 1H NMR chemical shift of clonazepam. Theoretical values are compared with the experimental data.展开更多
文摘滤波器组多载波(Filter Bank Multi-Carrier,FBMC)是5G移动通信系统中可能替代OFDM的调制方式,但是其峰均比(Peak to Average Power Ratio,PAPR)较高。DFT扩频技术利用DFT扩展输入信号,将FBMC信号的PAPR降到单载波传输的水平,但是仍存在缺点:经过推导发现,在同一符号周期内,传输符号x(t)中有4种不同的符号,导致PAPR值较高。因此,对DFT扩频技术中的相移项进行改进,提出了一种基于多载波等时移条件的DFT扩频(Identically Time Shifted Multicarrier-DFT spreading,ITSM-DFTs)算法。该算法充分利用了DFT扩频技术的单载波效应,理论分析和仿真结果表明,该算法有效降低了FBMC系统的PAPR。
基金Supported by the National High Technology Research and Development Program of China (2006AA01Z226)
文摘In this paper, an Ethernet controller SoC solution and its low power design for testability （DFT） for information appliances are presented. On a single chip, an enhanced one-cycle 8-bit micro controller unit （MCU）, media access control （MAC） circuit and embedded memories such as static random access memory （SRAM）, read only memory （ROM） and flash are all integrated together. In order to achieve high fault coverage, at the same time with low test power, different DFT techniques are adopted for different circuits： the scan circuit that reduces switching activity is implemented for digital logic circuits; BIST-based method is employed for the on-chip SRAM and ROM. According to the fault-modeling of embedded flash, we resort to a March-like method for flash built in self test （BIST）. By all means above, the result shows that the fault coverage may reach 97%, and the SoC chip is implemented successfully by using 0.25 μm two-poly four-metal mixed signal complementary metal oxide semiconductor （CMOS） technology, the die area is 4.8×4.6 mm^2. Test results show that the maximum throughput of Ethemet packets may reach 7Mb·s^1.
文摘Quantum chemical calculations have been carried out to investigate the vibrational frequencies of clonazepam. The FTIR spectrum of clonazepam was recorded in the region 4000 to 400 cm–1 in the solid phase. The optimized geometry, wave number and intensity of the vibrational bands of clonazepam were obtained by ab initio Restricted Hartree Fock (RHF) and Density Functional Theory (DFT) methods with complete relaxation in the potential energy surface using the 6-31G (d,p) basis set. A complete vibrational assignment aided by the theoretical harmonic frequency analysis is proposed. The observed and the calculated wavenumbers are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretical spectra. Theoretical spectrograms for the IR spectrum were also constructed in RHF and B3LYP levels. In addition to this the RHF and DFT based NMR calculation procedure was used to assign the 1H NMR chemical shift of clonazepam. Theoretical values are compared with the experimental data.
