A communication system uses multiple communications links, preferably links that use different communications media. The multiple communications links may include a high latency/high bandwidth link using a fiber-optic cable configured to carry large volumes of data but having a high latency. The communications links may also include a low latency/low bandwidth link implemented using skywave propagation of radio waves and configured to carry smaller volumes of data with a lower latency across a substantial portion of the earth's surface. The two communications links may be used together to coordinate various activities such as the buying and selling of financial instruments.

A communication system uses multiple communications links, preferably links that use different communications media. The multiple communications links may include a high latency/high bandwidth link using a fiber-optic cable configured to carry large volumes of data but having a high latency. The communications links may also include a low latency/low bandwidth link implemented using skywave propagation of radio waves and configured to carry smaller volumes of data with a lower latency across a substantial portion of the earth's surface. The two communications links may be used together to coordinate various activities such as the buying and selling of financial instruments.

Embodiments of the present disclosure relate to methods, devices, apparatuses and computer readable storage media for signal source identification and determination. According to embodiments of the present disclosure, in response to detecting a signal, a device identifies at least one unit sequence from the signal. A bandwidth of each unit sequence is a common divisor of overlapping system bandwidths among a plurality of devices. The at least one unit sequence uniquely identifies a further device transmitting the signal. The device determines, based on the at least one unit sequence, the further device from the plurality of devices. As such, a device suffering interference due to atmospheric ducting can find out an interference source and perform an action to avoid the interference.

Embodiments of the present disclosure relate to methods, devices, apparatuses and computer readable storage media for signal source identification and determination. According to embodiments of the present disclosure, in response to detecting a signal, a device identifies at least one unit sequence from the signal. A bandwidth of each unit sequence is a common divisor of overlapping system bandwidths among a plurality of devices. The at least one unit sequence uniquely identifies a further device transmitting the signal. The device determines, based on the at least one unit sequence, the further device from the plurality of devices. As such, a device suffering interference due to atmospheric ducting can find out an interference source and perform an action to avoid the interference.

The present invention relates to a multi-carrier resource allocation method based on a wireless-powered backscatter communication network. The method comprises following steps: S1. constructing a wireless-powered backscatter communication system; S2: according to circuit power and transmit power constraints, establishing a resource allocation optimization problem taking a maximum total transmission rate of the system as an objective function; S3: according to the objective function and constraint conditions, decomposing an optimization sub-problem taking the transmit power of the backscatter transmitter as a variable; S4: after substituting optimal transmit power of the backscatter transmitter into an original problem, decomposing a sub-problems taking an energy allocation coefficient as a variable from an original optimization problem; S5: converting non-convex problems containing coupling variables into convex problems, creating a Lagrangian function, obtaining an optimal solution form according to a KKT condition, and iteratively updating corresponding variables using a gradient descent method until convergence.

The present invention relates to a multi-carrier resource allocation method based on a wireless-powered backscatter communication network. The method comprises following steps: S1. constructing a wireless-powered backscatter communication system; S2: according to circuit power and transmit power constraints, establishing a resource allocation optimization problem taking a maximum total transmission rate of the system as an objective function; S3: according to the objective function and constraint conditions, decomposing an optimization sub-problem taking the transmit power of the backscatter transmitter as a variable; S4: after substituting optimal transmit power of the backscatter transmitter into an original problem, decomposing a sub-problems taking an energy allocation coefficient as a variable from an original optimization problem; S5: converting non-convex problems containing coupling variables into convex problems, creating a Lagrangian function, obtaining an optimal solution form according to a KKT condition, and iteratively updating corresponding variables using a gradient descent method until convergence.

Technology for wireless transmission of messages to remote receiving devices is disclosed. The technology includes receiving a message for transmission, determining transmission parameters for transmission of the message, and transmitting the message to a remote receiving device according to the determined transmission parameters. The technology may also include encoding the message to effect message latency and may be employed for message transmission via the ionosphere or other atmospheric layer at frequencies in the Medium Frequency (MF), High Frequency (HF), or Very High Frequency (VHF) spectrum. Further, the disclosed technology may be employed for message transmission to effect low latency financial transaction execution, such as high speed high frequency trading.

The present disclosure relates to a skywave large-scale MIMO communication method, model, and system. A skywave communication base station in a short waveband is constructed using a large-scale antenna array, wherein skywave large-scale MIMO communication is carried out between the skywave communication base station and a user terminal in a coverage area by ionospheric reflection. The skywave communication base station determines a spacing of the large-scale antenna array according to a maximum operating frequency, and communicates with the user terminal based on a TDD communication mode, wherein a skywave large-scale MIMO signal is transmitted based on an OFDM modulation mode or a power efficiency improvement modulation mode. The skywave communication base station selects a communication carrier frequency within a short waveband range according to a real-time ionospheric channel characteristic, and adaptively selects an OFDM modulation parameter and a signal frame structure.

The present disclosure relates to a skywave large-scale MIMO communication method, model, and system. A skywave communication base station in a short waveband is constructed using a large-scale antenna array, wherein skywave large-scale MIMO communication is carried out between the skywave communication base station and a user terminal in a coverage area by ionospheric reflection. The skywave communication base station determines a spacing of the large-scale antenna array according to a maximum operating frequency, and communicates with the user terminal based on a TDD communication mode, wherein a skywave large-scale MIMO signal is transmitted based on an OFDM modulation mode or a power efficiency improvement modulation mode. The skywave communication base station selects a communication carrier frequency within a short waveband range according to a real-time ionospheric channel characteristic, and adaptively selects an OFDM modulation parameter and a signal frame structure.

A communication system uses skywave propagation to transmit data between communication nodes over a data transmission path. An atmospheric sensor is configured to collect atmospheric data at the reflection point of the data transmission path where the transmission path is redirected from the atmosphere toward the surface of the Earth. Data collected by the atmospheric sensor may be used to predict future ionospheric conditions and determine optimum working frequencies for transmission of data between the communication nodes.