PCM/PPK telemetry system is a multi-nary pulse modulation system.It is commonly used to transmit high-accuracy time information and some express signals.To the issue of security that telemetry data is transmitted in t...PCM/PPK telemetry system is a multi-nary pulse modulation system.It is commonly used to transmit high-accuracy time information and some express signals.To the issue of security that telemetry data is transmitted in the open space,a data encryption scheme in the PCM/PPK telemetry system is proposed.In this scheme,the PCM data of signal source are encrypted by stream cipher in which key streams are generated with clock control LSFR.The scheme can save system resource in the dual-modulation compound telemetry system.A backward key synchronization scheme is also proposed,which has the property of strong real-time and easy to implement.A simplified simulation model of PCM/PPK remote system is established based on the actual framework of telemetry system,and the model is simple and easy to simulate.The error performance of the system is analyzed in theory and tested by computer simulation.Also the security of the system is analyzed.The simulation and analysis results show that the encryption scheme can ensure the security of the telemetry data and does not cause error-diffusion.展开更多
A novel M-ary chirp modulation technique based on an optimal chirp signal design is proposed in this paper to offer higher data rate for an indoor wireless chirp spread spectrum communication system. Both linear chirp...A novel M-ary chirp modulation technique based on an optimal chirp signal design is proposed in this paper to offer higher data rate for an indoor wireless chirp spread spectrum communication system. Both linear chirp signals and combined chirp signals are used in this system to reduce the effect of the cross correlation, and simplify the complexity of the system. The optimal scheme of de- signing both linear chirp signals and combined chirp signals is discussed to minimize the value of the cross correlation and obtain a better system performance. Simulation results show that, compared with the binary orthogonal chirp modulation technique, the M-ary chirp modulation technique based on an optimal chirp signal set has a higher data rate with a reasonable bit-error rate （BER） perform- ance under both additive white gaussian noise （AWGN） channel and indoor wireless channel.展开更多
This is a paper about laser gyro sign a l processing circuit which is designed based on field-programmable gate array(FPGA) and digital signal processor(DSP).Through a pre-amplifier circuit,FPGA and DSP,a weak current...This is a paper about laser gyro sign a l processing circuit which is designed based on field-programmable gate array(FPGA) and digital signal processor(DSP).Through a pre-amplifier circuit,FPGA and DSP,a weak current signal is converted and transferred,then sent to the computer to display the final results.Through the laser gyro performance te sting,the obtained results coincide with those of the existing methods.Thus th e d esigned circuit realizes the function of laser gyro signal processing.展开更多
We experimentally demonstrate and analyze a 10 Gbit/s full duplex wavelength division multiplexing passive optical net- work （WDM-PON） system. A non-return-to-zero differential phase shift keying （NRZ-DPSK） modula...We experimentally demonstrate and analyze a 10 Gbit/s full duplex wavelength division multiplexing passive optical net- work （WDM-PON） system. A non-return-to-zero differential phase shift keying （NRZ-DPSK） modulation technique is first utilized for downlink direction, and then the downlink signal is re-modulated for the uplink direction using intensity modulation technique of on-off keying （0OK） with a data rate of 10 Gbit/s per channel. An effective colorless WDM-PON full duplex transmission system is achieved for the data rate of 10 Gbit/s per channel with a channel spacing of 60 GHz over the distance of 25 km with low power penalty.展开更多
This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network （WDM- PON） employing optical differentia/quadrature phase shift keying （DQPSK） downstream signals ...This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network （WDM- PON） employing optical differentia/quadrature phase shift keying （DQPSK） downstream signals and two different modulation formats of re-modulated upstream signals. At the optical line terminal （OLT）, 10 Gbit/s signal is modulated with DQPSK. At the optical network unit （ONU）, part of the downstream signal is re-modulated with on-offkeying （0OK） or inverse-return-to-zero （IRZ）. Simulation results show the impact on the system employing NRZ, RZ and carrier-suppressed return-to-zero （CSRZ）. The analyses also reflect that the architecture can restrain chromatic dispersion and channel crosstalk, which makes it the best architecture of access network in the future.展开更多
文摘PCM/PPK telemetry system is a multi-nary pulse modulation system.It is commonly used to transmit high-accuracy time information and some express signals.To the issue of security that telemetry data is transmitted in the open space,a data encryption scheme in the PCM/PPK telemetry system is proposed.In this scheme,the PCM data of signal source are encrypted by stream cipher in which key streams are generated with clock control LSFR.The scheme can save system resource in the dual-modulation compound telemetry system.A backward key synchronization scheme is also proposed,which has the property of strong real-time and easy to implement.A simplified simulation model of PCM/PPK remote system is established based on the actual framework of telemetry system,and the model is simple and easy to simulate.The error performance of the system is analyzed in theory and tested by computer simulation.Also the security of the system is analyzed.The simulation and analysis results show that the encryption scheme can ensure the security of the telemetry data and does not cause error-diffusion.
文摘A novel M-ary chirp modulation technique based on an optimal chirp signal design is proposed in this paper to offer higher data rate for an indoor wireless chirp spread spectrum communication system. Both linear chirp signals and combined chirp signals are used in this system to reduce the effect of the cross correlation, and simplify the complexity of the system. The optimal scheme of de- signing both linear chirp signals and combined chirp signals is discussed to minimize the value of the cross correlation and obtain a better system performance. Simulation results show that, compared with the binary orthogonal chirp modulation technique, the M-ary chirp modulation technique based on an optimal chirp signal set has a higher data rate with a reasonable bit-error rate （BER） perform- ance under both additive white gaussian noise （AWGN） channel and indoor wireless channel.
文摘This is a paper about laser gyro sign a l processing circuit which is designed based on field-programmable gate array(FPGA) and digital signal processor(DSP).Through a pre-amplifier circuit,FPGA and DSP,a weak current signal is converted and transferred,then sent to the computer to display the final results.Through the laser gyro performance te sting,the obtained results coincide with those of the existing methods.Thus th e d esigned circuit realizes the function of laser gyro signal processing.
基金supported by the National Basic Research program of China (No.2010CB328300)the Fundamental Research Funds for the Central Universities (No.2009RC0314)+2 种基金the National Natural Science Foundation of China (Nos.61077050, 61077014 and 60932004)the BUPT Young Foundation (No.2009CZ07)the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks (WRI) (No.2010OCTN-02)
文摘We experimentally demonstrate and analyze a 10 Gbit/s full duplex wavelength division multiplexing passive optical net- work （WDM-PON） system. A non-return-to-zero differential phase shift keying （NRZ-DPSK） modulation technique is first utilized for downlink direction, and then the downlink signal is re-modulated for the uplink direction using intensity modulation technique of on-off keying （0OK） with a data rate of 10 Gbit/s per channel. An effective colorless WDM-PON full duplex transmission system is achieved for the data rate of 10 Gbit/s per channel with a channel spacing of 60 GHz over the distance of 25 km with low power penalty.
基金supported by the National Internation Technology Cooperration(No.2012DFG12110)the National Natural Science Foundation of China(Nos.61077050and61077014)the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks(No.2010OCTN-02)
文摘This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network （WDM- PON） employing optical differentia/quadrature phase shift keying （DQPSK） downstream signals and two different modulation formats of re-modulated upstream signals. At the optical line terminal （OLT）, 10 Gbit/s signal is modulated with DQPSK. At the optical network unit （ONU）, part of the downstream signal is re-modulated with on-offkeying （0OK） or inverse-return-to-zero （IRZ）. Simulation results show the impact on the system employing NRZ, RZ and carrier-suppressed return-to-zero （CSRZ）. The analyses also reflect that the architecture can restrain chromatic dispersion and channel crosstalk, which makes it the best architecture of access network in the future.
