针对严格采样滤波多音调制(Filtered Multi-Tone modulation,FMT)系统符号间干扰严重的问题,通过推导严格采样FMT系统的矩阵表示式,提出了一种新的频域均衡算法,该算法以最大化比特速率为目标来确定均衡器的系数。仿真结果表明,在ATTC(A...针对严格采样滤波多音调制(Filtered Multi-Tone modulation,FMT)系统符号间干扰严重的问题,通过推导严格采样FMT系统的矩阵表示式,提出了一种新的频域均衡算法,该算法以最大化比特速率为目标来确定均衡器的系数。仿真结果表明,在ATTC(Advanced Television Technology Center)E型信道条件下,新算法的可达比特率(Achievable Bit Rate,ABR)性能比最小均方误差准则的线性均衡和判决反馈均衡分别提高了40%和70%,误码率性能在BER为10?4则分别改善了3dB和5dB;而在WLAN信道条件下,新算法的ABR性能分别提高了45%和75%,误码率性能在BER为10?4则分别改善了6dB和10dB。展开更多
该文根据"南理工一号"卫星发射任务,设计甚高频/特高频(VHF/UHF)卫星地面站系统,并成功实现信号的上下行功能。在分析立方体纳卫星通信特性的基础上,提出了适用于VHF/UHF频段的卫星地面站系统设计方案。针对卫星任务提出了音...该文根据"南理工一号"卫星发射任务,设计甚高频/特高频(VHF/UHF)卫星地面站系统,并成功实现信号的上下行功能。在分析立方体纳卫星通信特性的基础上,提出了适用于VHF/UHF频段的卫星地面站系统设计方案。针对卫星任务提出了音频频移键控(AFSK)调制与二进制相移键控(BPSK)解调实现方式,地面站系统采用硬件方式实现AFSK调制,利用基于Costas环的软件方式实现BPSK解调。实际测试表明,地面站上行功能良好,BPSK接收灵敏度达-120 d Bm,该系统可成功解调QB50P1和QB50P2等其他卫星信号。展开更多
This paper analyses the chanting of 21 five-syllable modem-style poems, which is Chinese traditional style of poem reciting with cadence and pleasant melody, in order to fmd out the prosodic hierarchy according to pau...This paper analyses the chanting of 21 five-syllable modem-style poems, which is Chinese traditional style of poem reciting with cadence and pleasant melody, in order to fmd out the prosodic hierarchy according to pause duration, and probe the phonetic features and methods of chanting. Results reveal that pause exists after ＂level-level＂ tonal combinations, which is a kind of metrical pattern of Chinese poetry. The duration of syllables doubles in sentence final position. An exclamation is added when the sentence ends with a checked syllable. The pitch of syllables with level tone is lower than that of syllables with oblique tones, alternation of level and oblique tones forms the chanting melody. Sentences and poems with same metrical pattern have the same chanting melody.展开更多
This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)c...This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation controlling.Simulation results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line failures.Comparison studies have also been performed between wind turbine pitch control and proposed method.展开更多
The purpose of this paper is to analyze the reception of Wagner＇s approaches to Greek antiquity by Greek musicologists and composers which took place at the first half of the 20th century. Wagner＇s such readings wer...The purpose of this paper is to analyze the reception of Wagner＇s approaches to Greek antiquity by Greek musicologists and composers which took place at the first half of the 20th century. Wagner＇s such readings were parts of wider narrations of archeology and how Greeks perceived their past.This research is largely based on primary sources of that time; its arguments construct two levels of critique： （1） Admiration （the ＇proper＇ aesthetic examples are German models, as exemplified in Wagner＇s work）; and （2） ＂Hellenism＂ as a means to distancing from Wagner （The past of ancient Greece is still believed to be better understood by the Greeks）. The principal conclusions are： （1） Wagner＇s views were admired because Wagner＇s example （ancient culture） should also be an example for Greek composers; and （2） Wagner＇s views were judged on the grounds of： Ideology： the expression of the ＂soul＂; the theory of ＂historic continuity＂; the balance between music, poetry, and dance; Wagner gave superiority to music, modem Greeks （should） give a predominant role to language as a means of expression in an ancient drama, or achieve a balance among the three arts of music, poetry, and dance.展开更多
This paper presents the flip-flop tone （FFT） DMAC protocol, a tone based MAC protocol using di- rectional antennas to solve the deafness problem, hidden terminal and exposed terminal problems simulta- neously. It us...This paper presents the flip-flop tone （FFT） DMAC protocol, a tone based MAC protocol using di- rectional antennas to solve the deafness problem, hidden terminal and exposed terminal problems simulta- neously. It uses two pairs of flip-flop tones. The first pair of tone is to send omni-directionally to reach every neighboring node to announce the start and the end of communication, and therefore to alleviate the deafness problem. The second pair of tone is to send directionally towards the sender. It is used to solve the hidden temlinal problem as well as the exposed terminal problem. Evaluation shows that FFT-DMAC can achieve better performance compared to the 802.11 and ToneDMAC protocol.展开更多
为了寻找适用于电力线载波通信(power line communications,PLC)系统的新调制解调方式,在电力线信道下对滤波多音调制(filtered multitone modulation,FMT)与正交频分复用(orthogonal frequency division multiplexing,OFDM)系统进行了...为了寻找适用于电力线载波通信(power line communications,PLC)系统的新调制解调方式,在电力线信道下对滤波多音调制(filtered multitone modulation,FMT)与正交频分复用(orthogonal frequency division multiplexing,OFDM)系统进行了性能比较。仿真结果表明,在给定的信道模型下,FMT系统在对抗频域脉冲噪声和窄带干扰方面优于OFDM系统,但在时域脉冲噪声下,性能比OFDM系统差。展开更多
文摘针对严格采样滤波多音调制(Filtered Multi-Tone modulation,FMT)系统符号间干扰严重的问题,通过推导严格采样FMT系统的矩阵表示式,提出了一种新的频域均衡算法,该算法以最大化比特速率为目标来确定均衡器的系数。仿真结果表明,在ATTC(Advanced Television Technology Center)E型信道条件下,新算法的可达比特率(Achievable Bit Rate,ABR)性能比最小均方误差准则的线性均衡和判决反馈均衡分别提高了40%和70%,误码率性能在BER为10?4则分别改善了3dB和5dB;而在WLAN信道条件下,新算法的ABR性能分别提高了45%和75%,误码率性能在BER为10?4则分别改善了6dB和10dB。
文摘该文根据"南理工一号"卫星发射任务,设计甚高频/特高频(VHF/UHF)卫星地面站系统,并成功实现信号的上下行功能。在分析立方体纳卫星通信特性的基础上,提出了适用于VHF/UHF频段的卫星地面站系统设计方案。针对卫星任务提出了音频频移键控(AFSK)调制与二进制相移键控(BPSK)解调实现方式,地面站系统采用硬件方式实现AFSK调制,利用基于Costas环的软件方式实现BPSK解调。实际测试表明,地面站上行功能良好,BPSK接收灵敏度达-120 d Bm,该系统可成功解调QB50P1和QB50P2等其他卫星信号。
文摘This paper analyses the chanting of 21 five-syllable modem-style poems, which is Chinese traditional style of poem reciting with cadence and pleasant melody, in order to fmd out the prosodic hierarchy according to pause duration, and probe the phonetic features and methods of chanting. Results reveal that pause exists after ＂level-level＂ tonal combinations, which is a kind of metrical pattern of Chinese poetry. The duration of syllables doubles in sentence final position. An exclamation is added when the sentence ends with a checked syllable. The pitch of syllables with level tone is lower than that of syllables with oblique tones, alternation of level and oblique tones forms the chanting melody. Sentences and poems with same metrical pattern have the same chanting melody.
文摘This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation controlling.Simulation results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line failures.Comparison studies have also been performed between wind turbine pitch control and proposed method.
文摘The purpose of this paper is to analyze the reception of Wagner＇s approaches to Greek antiquity by Greek musicologists and composers which took place at the first half of the 20th century. Wagner＇s such readings were parts of wider narrations of archeology and how Greeks perceived their past.This research is largely based on primary sources of that time; its arguments construct two levels of critique： （1） Admiration （the ＇proper＇ aesthetic examples are German models, as exemplified in Wagner＇s work）; and （2） ＂Hellenism＂ as a means to distancing from Wagner （The past of ancient Greece is still believed to be better understood by the Greeks）. The principal conclusions are： （1） Wagner＇s views were admired because Wagner＇s example （ancient culture） should also be an example for Greek composers; and （2） Wagner＇s views were judged on the grounds of： Ideology： the expression of the ＂soul＂; the theory of ＂historic continuity＂; the balance between music, poetry, and dance; Wagner gave superiority to music, modem Greeks （should） give a predominant role to language as a means of expression in an ancient drama, or achieve a balance among the three arts of music, poetry, and dance.
基金Supported by the National High Teehnology Research and Development Programme of China （No. 2006AA01Z172）；the Provincial Key Laboratory of Computer Information Processing Technology of Jiangsu Province （No. KJS0605）；Natural Science Foundation of China （No. 60573138） ；the National Key Basic Research and Development Progranane of China （No. 2006CB303000）.
文摘This paper presents the flip-flop tone （FFT） DMAC protocol, a tone based MAC protocol using di- rectional antennas to solve the deafness problem, hidden terminal and exposed terminal problems simulta- neously. It uses two pairs of flip-flop tones. The first pair of tone is to send omni-directionally to reach every neighboring node to announce the start and the end of communication, and therefore to alleviate the deafness problem. The second pair of tone is to send directionally towards the sender. It is used to solve the hidden temlinal problem as well as the exposed terminal problem. Evaluation shows that FFT-DMAC can achieve better performance compared to the 802.11 and ToneDMAC protocol.
文摘为了寻找适用于电力线载波通信(power line communications,PLC)系统的新调制解调方式,在电力线信道下对滤波多音调制(filtered multitone modulation,FMT)与正交频分复用(orthogonal frequency division multiplexing,OFDM)系统进行了性能比较。仿真结果表明,在给定的信道模型下,FMT系统在对抗频域脉冲噪声和窄带干扰方面优于OFDM系统,但在时域脉冲噪声下,性能比OFDM系统差。
