摘要 :
Amplitude shift keying (ASK), Frequency shift keying (FSK) and Phase Shift keying (PSK) are important digital modulation techniques. To generate these types of modulation various circuits are available. A new simple circuit for ge...
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Amplitude shift keying (ASK), Frequency shift keying (FSK) and Phase Shift keying (PSK) are important digital modulation techniques. To generate these types of modulation various circuits are available. A new simple circuit for generating amplitude shift keying, frequency-shift keying & phase-shift keying waves using sample & hold IC LF 398 is given. Simulation results which confirm the validity of the circuit are also included.
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摘要 :
Amplitude shift keying (ASK), Frequency shift keying (FSK) and Phase Shift keying (PSK) are important digital modulation techniques. To generate these types of modulation various circuits are available. A new simple circuit for ge...
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Amplitude shift keying (ASK), Frequency shift keying (FSK) and Phase Shift keying (PSK) are important digital modulation techniques. To generate these types of modulation various circuits are available. A new simple circuit for generating amplitude shift keying, frequency-shift keying & phase-shift keying waves using sample & hold IC LF 398 is given. Simulation results which confirm the validity of the circuit are also included.
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摘要 :
This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It include...
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This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It includes an approach for the implementation of three modulatorsmainly Amplitude Shift Keying modulator, Phase Shift Keying modulators and Frequency Shift Keying modulator in VHDL by means of Xilinx 13.1 and simulation in Modelsim. The same modulators has also been developed in MATLAB/SIMULINK environment. The various factors that affect the choice of a particular modulation technique have also been discussed and accordingly anyone of the techniques can be adopted taking into consideration the application.
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摘要 :
This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It include...
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This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It includes an approach for the implementation of three modulatorsmainly Amplitude Shift Keying modulator, Phase Shift Keying modulators and Frequency Shift Keying modulator in VHDL by means of Xilinx 13.1and simulation in Modelsim .The same modulators has also been developed in MATLAB/SIMULINK environment. The various factors that affect the choice of a particular modulation technique have also been discussed and accordingly anyone of the techniques can be adopted taking into consideration the application.
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摘要 :
This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It include...
展开
This paper presents the review of the different digital modulation techniques and the various methods and tools that are used to implement it on FPGA along with the design summary and logic utilization of the resources. It includes an approach for the implementation of three modulatorsmainly Amplitude Shift Keying modulator, Phase Shift Keying modulators and Frequency Shift Keying modulator in VHDL by means of Xilinx 13.1 and simulation in Modelsim. The same modulators has also been developed in MATLAB/SIMULINK environment. The various factors that affect the choice of a particular modulation technique have also been discussed and accordingly anyone of the techniques can be adopted taking into consideration the application.
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摘要 :
In wireless communication networks, the amplitude, phase, and frequency of a radio-frequency (RF) carrier is modulated to carry data signals. Generally, amplitude-shift keying (ASK), phase-shift keying (PSK) and frequency-shift ke...
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In wireless communication networks, the amplitude, phase, and frequency of a radio-frequency (RF) carrier is modulated to carry data signals. Generally, amplitude-shift keying (ASK), phase-shift keying (PSK) and frequency-shift keying (FSK) are served as the basic digital modulation formats. They are also the fundamental modulation schemes to form advanced modulation formats such as quadrature amplitude modulation (QAM) and quaternary phase-shift keying (QPSK). In order to extend the transmission distance of RF signals, radio-over-fiber technique has been proposed. In this context, it is highly desirable to generate ASK, PSK and FSK RF signals directly in the optical domain. In this paper, we report our recent works on the all-optical generation of ASK, PSK, and FSK RF signals based on cross polarization modulation (XPM) effect in nonlinear devices. For the generation of ASK RF signal, single-sideband (SSB) modulation and SSB upconversion is proposed to overcome the fiber chromatic dispersion induced power fading. Moreover, binary PSK RF signal is generated using XPM effect in a highly nonlinear fiber (HNLF). The precise phase shift of the PSK RF signal is independent of the optical power of the control beam. In addition, all-optical FSK RF signal is generated based on ASK to FSK modulation in an HNLF. The significant merit of this all-optical scheme is that the electrical bottleneck can be overcome thanks to the ultra-fast response of the nonlinear media. Thus, the carrier frequency of the phase-coded microwave signal is widely tunable. We have examined our schemes theoretically and experimentally. The proposed all-optical approach has the potential to realize uninterrupted transmission of the RF signals over fiber across different networks to the remote locations.
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摘要 :
In wireless communication networks, the amplitude, phase, and frequency of a radio-frequency (RF) carrier is modulated to carry data signals. Generally, amplitude-shift keying (ASK), phase-shift keying (PSK) and frequency-shift ke...
展开
In wireless communication networks, the amplitude, phase, and frequency of a radio-frequency (RF) carrier is modulated to carry data signals. Generally, amplitude-shift keying (ASK), phase-shift keying (PSK) and frequency-shift keying (FSK) are served as the basic digital modulation formats. They are also the fundamental modulation schemes to form advanced modulation formats such as quadrature amplitude modulation (QAM) and quaternary phase-shift keying (QPSK). In order to extend the transmission distance of RF signals, radio-over-fiber technique has been proposed. In this context, it is highly desirable to generate ASK, PSK and FSK RF signals directly in the optical domain. In this paper, we report our recent works on the all-optical generation of ASK, PSK, and FSK RF signals based on cross polarization modulation (XPM) effect in nonlinear devices. For the generation of ASK RF signal, single-sideband (SSB) modulation and SSB upconversion is proposed to overcome the fiber chromatic dispersion induced power fading. Moreover, binary PSK RF signal is generated using XPM effect in a highly nonlinear fiber (HNLF). The precise phase shift of the PSK RF signal is independent of the optical power of the control beam. In addition, all-optical FSK RF signal is generated based on ASK to FSK modulation in an HNLF. The significant merit of this all-optical scheme is that the electrical bottleneck can be overcome thanks to the ultra-fast response of the nonlinear media. Thus, the carrier frequency of the phase-coded microwave signal is widely tunable. We have examined our schemes theoretically and experimentally. The proposed all-optical approach has the potential to realize uninterrupted transmission of the RF signals over fiber across different networks to the remote locations.
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摘要 :
We developed the FPGA based evaluation platform of AMCC superimposition that communicate to CPRI transport tester, and systematically clarified the superimposition characteristics by evaluating several types of superimposition and...
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We developed the FPGA based evaluation platform of AMCC superimposition that communicate to CPRI transport tester, and systematically clarified the superimposition characteristics by evaluating several types of superimposition and detection scheme.
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摘要 :
We developed the FPGA based evaluation platform of AMCC superimposition that communicate to CPRI transport tester, and systematically clarified the superimposition characteristics by evaluating several types of superimposition and...
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We developed the FPGA based evaluation platform of AMCC superimposition that communicate to CPRI transport tester, and systematically clarified the superimposition characteristics by evaluating several types of superimposition and detection scheme.
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摘要 :
As well as transferring power, inductively coupled systems such as RFID and wireless charging commonly require a downlink channel to transfer data to the receiving function, for simplicity usually using the same carrier frequency ...
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As well as transferring power, inductively coupled systems such as RFID and wireless charging commonly require a downlink channel to transfer data to the receiving function, for simplicity usually using the same carrier frequency used for the power transfer. A high-Q resonant transmitter coil is highly desirable to create the strong magnetic field required fora practical operating range. However, this not only raises major problems with sensitivity to tolerances and environmental factors, but also seriously restricts the available bandwidth and hence downlink data-rate. Amplitude Shift or On-Off Keying (ASK/OOK) are commonly used to allow simple demodulation, but in addition to the 0 factor restricting the data-rate, the average power transfer will be reduced by around 50\%. Frequency Shift Keying (FSK) or Phase Shift Keying (PSK) are attractive inasmuch as the nominally constant envelope provides a potentially higher power throughput, but the data-rate issue with a high-Q transmitter still remains. This is obvious for FSK, where by definition operation cannot be maintained away from the transmitter antenna's resonance frequency. Less obviously, for PSK applied to a nominally constant frequency carrier, the stored energy in the transmit tuned circuit will slow the phase transitions making demodulation more difficult; for binary PSK the amplitude will also drop significantly at each symbol transition. Note that the receiver Q factor is usually lower to avoid the need for active tuning in a micropower circuit.
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