In radio receivers,complete implementation of the software defined radio(SDR) concept is mainly limited by frontend.Based on bandpass sampling(BPS) theory,a flexible digital frontend(DFE) platform for SDR receiver is ...In radio receivers,complete implementation of the software defined radio(SDR) concept is mainly limited by frontend.Based on bandpass sampling(BPS) theory,a flexible digital frontend(DFE) platform for SDR receiver is designed.In order to increase the processing speed,Gigabit Ethernet was applied in the platform at speed of 5×10~8 bit/s.By appropriate design of interpolant according to the position of input RF signals,multi-band receiving can be realized in the platform with suppression more than 35 d B without changing hardware.展开更多
Some structures of digital quadrature AD conversion for soft-ware-defined radio （SDR） systems are studied. Their performances and affections on the SDR systems are also analyzed. Two generalized quadrature AD scheme...Some structures of digital quadrature AD conversion for soft-ware-defined radio （SDR） systems are studied. Their performances and affections on the SDR systems are also analyzed. Two generalized quadrature AD schemes are proposed. In one of them, the AD sampling speed can be reduced by 2 times; and in the other both the output data rate of every channel and AD sampling speed can be lowered by paralleling the digital quadrature filtering structure. These structures can be also easily implemented into modules, and the polyphase filters can be flexibly realized by VHDL language based one chip of FPGA. To assess the proposed schemes, their applications to a particular ultra wideband （UWB） demonstrative receiver system are introduced. Some experimental results are also given. It is shown that the generalized quadrature AD structures are reliable and feasible for its module design, and performances are improved obviously for its better performance to price ratio.展开更多
The widespread 5G base stations can be potential jammers for the vulnerable BeiDou B1I receivers due to its low power.Therefore,a novel analytical model is derived for the 5G signal to evaluate its impact on acquisiti...The widespread 5G base stations can be potential jammers for the vulnerable BeiDou B1I receivers due to its low power.Therefore,a novel analytical model is derived for the 5G signal to evaluate its impact on acquisition performance under three decision methods.The good agreement between the Monte Carlo method(MCM)through software defined receiver(SDR)and the derived expressions validates the effectiveness of the proposed algorithm.It can be found that the receivers exhibit varied responses for different 5G waveforms and decision strategies.The receiver also shows the least endurances for some kind of 5G waveforms,however,this kind of adverse effect can be cancelled by a reduced interference signal ratio(ISR),an increased integration time or a larger accumulation times.展开更多
基金Project(2013QNA49)supported by the Fundamental Research Funds for the Central Universities,China
文摘In radio receivers,complete implementation of the software defined radio(SDR) concept is mainly limited by frontend.Based on bandpass sampling(BPS) theory,a flexible digital frontend(DFE) platform for SDR receiver is designed.In order to increase the processing speed,Gigabit Ethernet was applied in the platform at speed of 5×10~8 bit/s.By appropriate design of interpolant according to the position of input RF signals,multi-band receiving can be realized in the platform with suppression more than 35 d B without changing hardware.
基金This project was part financially supported by Natural Science Researching Project for Jiangsu Universities (03KJB510130, 05KJD510177 and NSFC.60572075).
文摘Some structures of digital quadrature AD conversion for soft-ware-defined radio （SDR） systems are studied. Their performances and affections on the SDR systems are also analyzed. Two generalized quadrature AD schemes are proposed. In one of them, the AD sampling speed can be reduced by 2 times; and in the other both the output data rate of every channel and AD sampling speed can be lowered by paralleling the digital quadrature filtering structure. These structures can be also easily implemented into modules, and the polyphase filters can be flexibly realized by VHDL language based one chip of FPGA. To assess the proposed schemes, their applications to a particular ultra wideband （UWB） demonstrative receiver system are introduced. Some experimental results are also given. It is shown that the generalized quadrature AD structures are reliable and feasible for its module design, and performances are improved obviously for its better performance to price ratio.
文摘The widespread 5G base stations can be potential jammers for the vulnerable BeiDou B1I receivers due to its low power.Therefore,a novel analytical model is derived for the 5G signal to evaluate its impact on acquisition performance under three decision methods.The good agreement between the Monte Carlo method(MCM)through software defined receiver(SDR)and the derived expressions validates the effectiveness of the proposed algorithm.It can be found that the receivers exhibit varied responses for different 5G waveforms and decision strategies.The receiver also shows the least endurances for some kind of 5G waveforms,however,this kind of adverse effect can be cancelled by a reduced interference signal ratio(ISR),an increased integration time or a larger accumulation times.
