With the development of the transportation industry, the effective guidance of aircraft in an emergency to prevent catastrophic accidents remains one of the top safety concerns. Undoubtedly, operational status data of...With the development of the transportation industry, the effective guidance of aircraft in an emergency to prevent catastrophic accidents remains one of the top safety concerns. Undoubtedly, operational status data of the aircraft play an important role in the judgment and command of the Operational Control Center(OCC). However, how to transmit various operational status data from abnormal aircraft back to the OCC in an emergency is still an open problem. In this paper, we propose a novel Telemetry, Tracking,and Command(TT&C) architecture named Collaborative TT&C(CoTT&C) based on mega-constellation to solve such a problem. CoTT&C allows each satellite to help the abnormal aircraft by sharing TT&C resources when needed, realizing real-time and reliable aeronautical communication in an emergency. Specifically, we design a dynamic resource sharing mechanism for CoTT&C and model the mechanism as a single-leader-multi-follower Stackelberg game. Further, we give an unique Nash Equilibrium(NE) of the game as a closed form. Simulation results demonstrate that the proposed resource sharing mechanism is effective, incentive compatible, fair, and reciprocal. We hope that our findings can shed some light for future research on aeronautical communications in an emergency.展开更多
The aeronautical en-route communication channel is modeled as a two-ray double-selective channel. Based on the channel model, a low-eomplexity iteration self-cancellation algorithm is proposed to cancel the inter-carr...The aeronautical en-route communication channel is modeled as a two-ray double-selective channel. Based on the channel model, a low-eomplexity iteration self-cancellation algorithm is proposed to cancel the inter-carrier interference （ICI） of orthogonal frequency division multiplexing （OFDM） system in aeronautical communications. ICI can be completely suppressed by the proposed algorithm if channel parameters are estimated ideally. We analyzed the SNR loss with variant iteration times theoretically, and pointed out how to choose the optimum iteration times. The algorithm is especially useful to the situation with high aviation veloc- ity, as less iteration is sufficient to separate the interference with larger Doppler shift, and less noise will he introduced. We carried out Monte Carlo simulation with typical aeronautical en-route channel, and the simulation results are in agreement with the deduced theoretical performance expressions and validate the effect of our cancellation algorithm.展开更多
In aeronautical mobile communication systems,wireless channels characteristics are dif-ferent in scenarios of Parking,En-Route,Taxi,and Arrival/Take-off.By considering fading types,power spectrum density and delay cha...In aeronautical mobile communication systems,wireless channels characteristics are dif-ferent in scenarios of Parking,En-Route,Taxi,and Arrival/Take-off.By considering fading types,power spectrum density and delay characterization of aeronautical wireless channels,typical parame-ters of aeronautical wireless channels model are investigated to analyze characteristics of aeronautical wireless channels.展开更多
Attacking time-sensitive targets has rigid demands for the timeliness and reliability of information transmission, while typical Media Access Control（MAC） designed for this application works well only in very light-...Attacking time-sensitive targets has rigid demands for the timeliness and reliability of information transmission, while typical Media Access Control（MAC） designed for this application works well only in very light-load scenarios; as a consequence, the performances of system throughput and channel utilization are degraded. For this problem, a feedback-retransmission based asynchronous FRequency hopping Media Access（FRMA） control protocol is proposed. Burst communication, asynchronous Frequency Hopping（FH）, channel coding, and feedback retransmission are utilized in FRMA. With the mechanism of asynchronous FH, immediate packet transmission and multi-packet reception can be realized, and thus the timeliness is improved.Furthermore, reliability can be achieved via channel coding and feedback retransmission. With theories of queuing theory, Markov model, packets collision model, and discrete Laplace transformation, the formulas of packet success probability, system throughput, average packet end-to-end delay, and delay distribution are obtained. The approximation accuracy of theoretical derivation is verified by experimental results. Within a light-load network, the proposed FRMA has the ability of millisecond delay and 99% reliability as well as outperforms the non-feedback-retransmission based asynchronous frequency hopping media access control protocol.展开更多
基金supported by the National Natural Science Foundation of China under Grant 62131012/61971261。
文摘With the development of the transportation industry, the effective guidance of aircraft in an emergency to prevent catastrophic accidents remains one of the top safety concerns. Undoubtedly, operational status data of the aircraft play an important role in the judgment and command of the Operational Control Center(OCC). However, how to transmit various operational status data from abnormal aircraft back to the OCC in an emergency is still an open problem. In this paper, we propose a novel Telemetry, Tracking,and Command(TT&C) architecture named Collaborative TT&C(CoTT&C) based on mega-constellation to solve such a problem. CoTT&C allows each satellite to help the abnormal aircraft by sharing TT&C resources when needed, realizing real-time and reliable aeronautical communication in an emergency. Specifically, we design a dynamic resource sharing mechanism for CoTT&C and model the mechanism as a single-leader-multi-follower Stackelberg game. Further, we give an unique Nash Equilibrium(NE) of the game as a closed form. Simulation results demonstrate that the proposed resource sharing mechanism is effective, incentive compatible, fair, and reciprocal. We hope that our findings can shed some light for future research on aeronautical communications in an emergency.
基金Sponsored by the National"863" Program Project(2007AA01Z293)
文摘The aeronautical en-route communication channel is modeled as a two-ray double-selective channel. Based on the channel model, a low-eomplexity iteration self-cancellation algorithm is proposed to cancel the inter-carrier interference （ICI） of orthogonal frequency division multiplexing （OFDM） system in aeronautical communications. ICI can be completely suppressed by the proposed algorithm if channel parameters are estimated ideally. We analyzed the SNR loss with variant iteration times theoretically, and pointed out how to choose the optimum iteration times. The algorithm is especially useful to the situation with high aviation veloc- ity, as less iteration is sufficient to separate the interference with larger Doppler shift, and less noise will he introduced. We carried out Monte Carlo simulation with typical aeronautical en-route channel, and the simulation results are in agreement with the deduced theoretical performance expressions and validate the effect of our cancellation algorithm.
文摘In aeronautical mobile communication systems,wireless channels characteristics are dif-ferent in scenarios of Parking,En-Route,Taxi,and Arrival/Take-off.By considering fading types,power spectrum density and delay characterization of aeronautical wireless channels,typical parame-ters of aeronautical wireless channels model are investigated to analyze characteristics of aeronautical wireless channels.
基金supported by the National Natural Science Foundation of China(No.61501496)
文摘Attacking time-sensitive targets has rigid demands for the timeliness and reliability of information transmission, while typical Media Access Control（MAC） designed for this application works well only in very light-load scenarios; as a consequence, the performances of system throughput and channel utilization are degraded. For this problem, a feedback-retransmission based asynchronous FRequency hopping Media Access（FRMA） control protocol is proposed. Burst communication, asynchronous Frequency Hopping（FH）, channel coding, and feedback retransmission are utilized in FRMA. With the mechanism of asynchronous FH, immediate packet transmission and multi-packet reception can be realized, and thus the timeliness is improved.Furthermore, reliability can be achieved via channel coding and feedback retransmission. With theories of queuing theory, Markov model, packets collision model, and discrete Laplace transformation, the formulas of packet success probability, system throughput, average packet end-to-end delay, and delay distribution are obtained. The approximation accuracy of theoretical derivation is verified by experimental results. Within a light-load network, the proposed FRMA has the ability of millisecond delay and 99% reliability as well as outperforms the non-feedback-retransmission based asynchronous frequency hopping media access control protocol.
