The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The pot...The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.展开更多
In order to realize broadband and high-speed transmission in the last mile access network,the Coded Wavelength-Division Multiplexing(Coded-WDM)technique on PON(so-called CDM-PON)is presented on fiber-to-the-home acces...In order to realize broadband and high-speed transmission in the last mile access network,the Coded Wavelength-Division Multiplexing(Coded-WDM)technique on PON(so-called CDM-PON)is presented on fiber-to-the-home access network.In this paper,the codcd-WDM coder/decoder(codec}is configured on Optical Network Unit(ONU)and Optical Line Terminal(OLT)in Ethemet Passive Optical Network(E-PON).Here,network codecs are constructed with Arrayed Waveguide Grating(AWG)devices and the signature address code is employed as complementary Walsh code whose original code is for data bit'1'and complementary code is for data bit'0'respectively.It is shown that the simultaneous active user of proposed scheme using CWH code is improved 100%than using M-Sequence and conventional Walsh code for given bit error rate of 10^-9.In addition,the signal to noise ratio(SNR)performance is improved by 6dB compared with conventional scheme employed M-sequence and Walsh code.展开更多
The researches on spectral amplitude correlation between successive frames based on MBE (Multi-Band Excitation) are presented and a new MBE coding algorithm of muitimodels is proposed. It has been shown that the magni...The researches on spectral amplitude correlation between successive frames based on MBE (Multi-Band Excitation) are presented and a new MBE coding algorithm of muitimodels is proposed. It has been shown that the magnitude spectrum in MBE coding algorithm can be estimated in very high accuracy by using a simple linear predictive model of the spectral amplitude correlation between successive frames. This model employs oniy one gain coefficient and one predictive coefficient. The accuracy of estimated magnitude spectrum in this model is higher than that of the conventional MBE algorithm using the 10-th order LPC (Linear Predictive Coding) Inodel without the spectral amplitude correlation between successlve frames.This model is superior to the conventional MBE coding model in volced speech, but it is iess effective in unvoiced speech, so that the conventional MBE coding algorithm is still used for unvoiced speech. The new multi-model coding algorithm improves the quality of coding speech,and obtains good results展开更多
We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label...We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor （EOF） and bit-error rate （BER） at 10 9 as a function of the received optical power （ROP） and the optical signal to noise ratio （OSNR）. The payload could well be demodulated after 900 km at a bit error rate of 10-3 using forward error correction （FEC）.展开更多
基金Supported by the National High Technology Research and Development Program of China(863Program)(2011AA120502)
文摘The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.
文摘In order to realize broadband and high-speed transmission in the last mile access network,the Coded Wavelength-Division Multiplexing(Coded-WDM)technique on PON(so-called CDM-PON)is presented on fiber-to-the-home access network.In this paper,the codcd-WDM coder/decoder(codec}is configured on Optical Network Unit(ONU)and Optical Line Terminal(OLT)in Ethemet Passive Optical Network(E-PON).Here,network codecs are constructed with Arrayed Waveguide Grating(AWG)devices and the signature address code is employed as complementary Walsh code whose original code is for data bit'1'and complementary code is for data bit'0'respectively.It is shown that the simultaneous active user of proposed scheme using CWH code is improved 100%than using M-Sequence and conventional Walsh code for given bit error rate of 10^-9.In addition,the signal to noise ratio(SNR)performance is improved by 6dB compared with conventional scheme employed M-sequence and Walsh code.
文摘The researches on spectral amplitude correlation between successive frames based on MBE (Multi-Band Excitation) are presented and a new MBE coding algorithm of muitimodels is proposed. It has been shown that the magnitude spectrum in MBE coding algorithm can be estimated in very high accuracy by using a simple linear predictive model of the spectral amplitude correlation between successive frames. This model employs oniy one gain coefficient and one predictive coefficient. The accuracy of estimated magnitude spectrum in this model is higher than that of the conventional MBE algorithm using the 10-th order LPC (Linear Predictive Coding) Inodel without the spectral amplitude correlation between successlve frames.This model is superior to the conventional MBE coding model in volced speech, but it is iess effective in unvoiced speech, so that the conventional MBE coding algorithm is still used for unvoiced speech. The new multi-model coding algorithm improves the quality of coding speech,and obtains good results
文摘We present the performance analysis of ll2Gb/s-4 wavelength division multiplexing （WDM） 100GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying （PDM-DQPSK） optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor （EOF） and bit-error rate （BER） at 10 9 as a function of the received optical power （ROP） and the optical signal to noise ratio （OSNR）. The payload could well be demodulated after 900 km at a bit error rate of 10-3 using forward error correction （FEC）.
