Based on the proposed partly equidifferent mapping and its specific Differential Amplitude and Pulse Position Modulation(DAPPM) demodulation, a modified FSO scheme for turbulent channel is designed and analyzed. The n...Based on the proposed partly equidifferent mapping and its specific Differential Amplitude and Pulse Position Modulation(DAPPM) demodulation, a modified FSO scheme for turbulent channel is designed and analyzed. The novel Low Density Parity Check(LDPC) coded 4×4 and 4×8 DAPPM Free-Space Optical communication(FSO) system is constructed. The Monte Carlo simulation results show approximately 2d B transmit power reduction against classical LDPC-DAPPM at the identical Bit-Error-Rate in strong turbulent channel. The proposed partly equidifferent mapping is compatible with other modulations, so it enables widespread adoption in other coded FSO systems.展开更多
Supervisory Control and Data Acquisition （SCADA） is used broadly to portray control and management solutions in a wide range of industries. SCADA system failure may lead to disastrous consequences since the health a...Supervisory Control and Data Acquisition （SCADA） is used broadly to portray control and management solutions in a wide range of industries. SCADA system failure may lead to disastrous consequences since the health and the safety of the public as the economic viability of the community it serves depends on it. After its introduction in DPDC over a decade ago, the SCADA system hardly had any performance upgradation. Currently, the microwave link in SCADA Communication is observing problems that are rendering the entire structure obsolete. This paper revises the possibility to implement a new communication technology and proposes Free Space Optical （FSO） communication to enhance SCADA system reliability. FSO refers to the transmission of modulated visible or infrared （IR） beams through the air to obtain optical communication. Like optical fiber, FSO also uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, the data is transmitted through the air. It is a secure, cost-effective alternative to other wireless connectivity options.展开更多
A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is pr...A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is proposed. Regarding the addressed scenario, when the propagation link between HAPS and train is blocked by obstacles, a three-dimensional （3-D） geometrical single cylinder spatial-temporal channel model is presented, in which closed form, mathematically tractable space-time correlation functions are obtained. It shows that the correlation functions determined by the 3-D model are of significant difference with those of the conventional 2-D model. Based on the analysis model, the paper derives a realized simulation model using sum-of-sinusoids approach, and applies method of equal areas （MEA） and modified method of equal areas （MMEA） to determine the model parameters. The fitting performance of the simulation model with the analysis one is evaluated by two means-square error （MSE） performance criteria. Finally, numerical simulation results verify the mathematical analysis conclusion, when N ≥21, simulation model has an excellent fitness with the analysis one.展开更多
基金supported by the National High-tech R&D Program (863 Program) 2013AA041003the Natural Science Foundation of China under Grants 51165033the Science and Technology Department of Jiangxi Province of China under grant 20151BBE50046,20142BBE50035 and 20151BAB207052
文摘Based on the proposed partly equidifferent mapping and its specific Differential Amplitude and Pulse Position Modulation(DAPPM) demodulation, a modified FSO scheme for turbulent channel is designed and analyzed. The novel Low Density Parity Check(LDPC) coded 4×4 and 4×8 DAPPM Free-Space Optical communication(FSO) system is constructed. The Monte Carlo simulation results show approximately 2d B transmit power reduction against classical LDPC-DAPPM at the identical Bit-Error-Rate in strong turbulent channel. The proposed partly equidifferent mapping is compatible with other modulations, so it enables widespread adoption in other coded FSO systems.
文摘Supervisory Control and Data Acquisition （SCADA） is used broadly to portray control and management solutions in a wide range of industries. SCADA system failure may lead to disastrous consequences since the health and the safety of the public as the economic viability of the community it serves depends on it. After its introduction in DPDC over a decade ago, the SCADA system hardly had any performance upgradation. Currently, the microwave link in SCADA Communication is observing problems that are rendering the entire structure obsolete. This paper revises the possibility to implement a new communication technology and proposes Free Space Optical （FSO） communication to enhance SCADA system reliability. FSO refers to the transmission of modulated visible or infrared （IR） beams through the air to obtain optical communication. Like optical fiber, FSO also uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, the data is transmitted through the air. It is a secure, cost-effective alternative to other wireless connectivity options.
基金Supported by the National Natural Science Foundation of China (No. 60532030).
文摘A high altitude platform station （HAPS） based communications scenario for providing Intemet access and broadband multimedia services to the passengers on board of a high speed train （traveling up to 300km/h） is proposed. Regarding the addressed scenario, when the propagation link between HAPS and train is blocked by obstacles, a three-dimensional （3-D） geometrical single cylinder spatial-temporal channel model is presented, in which closed form, mathematically tractable space-time correlation functions are obtained. It shows that the correlation functions determined by the 3-D model are of significant difference with those of the conventional 2-D model. Based on the analysis model, the paper derives a realized simulation model using sum-of-sinusoids approach, and applies method of equal areas （MEA） and modified method of equal areas （MMEA） to determine the model parameters. The fitting performance of the simulation model with the analysis one is evaluated by two means-square error （MSE） performance criteria. Finally, numerical simulation results verify the mathematical analysis conclusion, when N ≥21, simulation model has an excellent fitness with the analysis one.
