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RISS 인기검색어
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- 저자 : Zhidong Xie (검색결과 5 건)
- 무료
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- 유료
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Constant Envelope Enhanced FQPSK and Its Performance Analysis
Xie, Zhidong,Zhang, Gengxin,Bian, Dongming The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.5
It's a challenging task to design a high performance modulation for satellite and space communications due to the limited power and bandwidth resource. Constant envelope modulation is an attractive scheme to be used in such cases for their needlessness of input power back-off about 2~3 dB for avoidance of nonlinear distortion induced by high power amplifier. The envelope of Feher quadrature phase shift keying (FQPSK) has a least fluctuation of 0.18 dB (quasi constant envelope) and can be further improved. This paper improves FQPSK by defining a set of new waveform functions, which changes FQPSK to be a strictly constant envelope modulation. The performance of the FQPSK adopting new waveform is justified by analysis and simulation. The study results show that the novel FQPSK is immune to the impact of HPA and outperforms conventional FQPSK on bit error rate (BER) performance. The BER performance of this novel modulation is better than that of FQPSK by more than 0.5 dB at least and 2 dB at most.
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Constant Envelope Enhanced FQPSK and Its Performance Analysis
Zhidong Xie,Gengxin Zhang,Dongming Bian 한국통신학회 2011 Journal of communications and networks Vol.13 No.5
It’s a challenging task to design a high performance modulation for satellite and space communications due to the limited power and bandwidth resource. Constant envelope modulation is an attractive scheme to be used in such cases for their needlessness of input power back-off about 2∼3 dB for avoidance of nonlinear distortion induced by high power amplifier. The envelope of Feher quadrature phase shift keying (FQPSK) has a least fluctuation of 0.18 dB (quasi constant envelope) and can be further improved. This paper improves FQPSK by defining a set of new waveform functions, which changes FQPSK to be a strictly constant envelope modulation. The performance of the FQPSK adopting new waveform is justified by analysis and simulation. The study results show that the novel FQPSK is immune to the impact of HPA and outperforms conventional FQPSK on bit error rate (BER) performance. The BER performance of this novel modulation is better than that of FQPSK by more than 0.5 dB at least and 2 dB at most.
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Data Dissemination in Wireless Sensor Networks with Instantly Decodable Network Coding
Gou, Liang,Zhang, Gengxin,Bian, Dongming,Zhang, Wei,Xie, Zhidong The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.5
Wireless sensor networks (WSNs) are widely applied in monitoring and control of environment parameters. It is sometimes necessary to disseminate data through wireless links after they are deployed in order to adjust configuration parameters of sensors or distribute management commands and queries to sensors. Several approaches have been proposed recently for data dissemination in WSNs. However, none of these approaches achieves both high efficiency and low complexity simultaneously. To address this problem, cluster-tree based network architecture, which divides a WSN into hierarchies and clusters is proposed. Upon this architecture, data is delivered from base station to all sensors in clusters hierarchy by hierarchy. In each cluster, father broadcasts data to all his children with instantly decodable network coding (IDNC), and a novel scheme targeting to maximize total transmission gain (MTTG) is proposed. This scheme employs a new packet scheduling algorithm to select IDNC packets, which uses weight status feedback matrix (WSFM) directly. Analysis and simulation results indicate that the transmission efficiency approximate to the best existing approach maximum weight clique, but with much lower computational overhead. Hence, the energy efficiency achieves both in data transmission and processing.
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Data Dissemination in Wireless Sensor Networks with Instantly Decodable Network Coding
Liang Gou,Gengxin Zhang,Dongming Bian,Wei Zhang,Zhidong Xie 한국통신학회 2016 Journal of communications and networks Vol.18 No.5
Wireless sensor networks (WSNs) are widely applied inmonitoring and control of environment parameters. It is sometimesnecessary to disseminate data through wireless links after they aredeployed in order to adjust configuration parameters of sensors ordistribute management commands and queries to sensors. Severalapproaches have been proposed recently for data dissemination inWSNs. However, none of these approaches achieves both high effi-ciency and low complexity simultaneously. To address this problem,cluster-tree based network architecture, which divides aWSN intohierarchies and clusters is proposed. Upon this architecture, datais delivered from base station to all sensors in clusters hierarchyby hierarchy. In each cluster, father broadcasts data to all his chil-dren with instantly decodable network coding (IDNC), and a novelscheme targeting to maximize total transmission gain (MTTG) isproposed. This scheme employs a new packet scheduling algorithmto select IDNC packets, which uses weight status feedback matrix(WSFM) directly. Analysis and simulation results indicate that thetransmission efficiency approximate to the best existing approachmaximum weight clique, but with much lower computational over-head. Hence, the energy efficiency achieves both in data transmis-sion and processing.
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