A first offset compensator configured to compensate for frequency offsets occurring during communications between a plurality of communication devices and a relay device, wherein when the first offset compensator is provided on the relay device, the first offset compensator gives a statistical frequency offset obtained from a statistic of a plurality of frequency offsets occurring during communications between respective ones of the plurality of communication devices and the relay device to a receiver configured to receive wireless signals transmitted from respective ones of the plurality of communication devices, and when the first offset compensator is provided on each of the plurality of communication devices, the first offset compensator gives a frequency offset occurring during communications between the communication device provided with the first offset compensator and the relay device to a transmitter configured to transmit wireless signals to the relay device.

A first offset compensator configured to compensate for frequency offsets occurring during communications between a plurality of communication devices and a relay device, wherein when the first offset compensator is provided on the relay device, the first offset compensator gives a statistical frequency offset obtained from a statistic of a plurality of frequency offsets occurring during communications between respective ones of the plurality of communication devices and the relay device to a receiver configured to receive wireless signals transmitted from respective ones of the plurality of communication devices, and when the first offset compensator is provided on each of the plurality of communication devices, the first offset compensator gives a frequency offset occurring during communications between the communication device provided with the first offset compensator and the relay device to a transmitter configured to transmit wireless signals to the relay device.

A satellite receiver for wireless signals having carrier frequencies in the V or the W band of frequencies is described. The satellite receiver may receive the wireless signals at high elevation angles, such as greater than 62° . This high elevation angle may reduce losses, which may allow the satellite receiver to communicate at a data rate of at least 50 Mbps. In order to accommodate these system requirements, the one or more satellites that provide the wireless signals may have eccentric geosynchronous or near-geosynchronous orbits that are inclined relative to an equatorial plane of the Earth, such as an eccentricity between 0.12 and 0.3. Moreover, the one or more satellites may have ground tracks substantially along one or more continents, and may be in view of dense population regions in the one or more continents with a higher frequency than low-density population regions in the one or more continents.

A satellite receiver for wireless signals having carrier frequencies in the V or the W band of frequencies is described. The satellite receiver may receive the wireless signals at high elevation angles, such as greater than 62° . This high elevation angle may reduce losses, which may allow the satellite receiver to communicate at a data rate of at least 50 Mbps. In order to accommodate these system requirements, the one or more satellites that provide the wireless signals may have eccentric geosynchronous or near-geosynchronous orbits that are inclined relative to an equatorial plane of the Earth, such as an eccentricity between 0.12 and 0.3. Moreover, the one or more satellites may have ground tracks substantially along one or more continents, and may be in view of dense population regions in the one or more continents with a higher frequency than low-density population regions in the one or more continents.

An operation method of a first communication node in a communication system may comprise receiving one or more transport blocks (TBs) from a second communication node based on transmission parameters in an aggregated transmission period #n; generating decoding results for the one or more TBs; generating information required for changing the transmission parameters based on the decoding results; and transmitting the required information to the second communication node, wherein n is a natural number.

An operation method of a first communication node in a communication system may comprise receiving one or more transport blocks (TBs) from a second communication node based on transmission parameters in an aggregated transmission period #n; generating decoding results for the one or more TBs; generating information required for changing the transmission parameters based on the decoding results; and transmitting the required information to the second communication node, wherein n is a natural number.

In one example, an antenna system is described. The antenna system includes a primary antenna on an aircraft. The primary antenna is mechanically steerable and has an asymmetric antenna beam pattern with a narrow beamwidth axis and a wide beamwidth axis at boresight. The antenna system also includes a secondary antenna on the aircraft, the secondary antenna including an array of antenna elements. The antenna system also includes an antenna selection system to control communication of a signal between the aircraft and a target satellite via the primary antenna and the secondary antenna. The antenna selection system switches communication of the signal from the primary antenna to the secondary antenna when a performance characteristic for communication with the target satellite satisfies a threshold due to a position of the aircraft relative to the target satellite.

In one example, an antenna system is described. The antenna system includes a primary antenna on an aircraft. The primary antenna is mechanically steerable and has an asymmetric antenna beam pattern with a narrow beamwidth axis and a wide beamwidth axis at boresight. The antenna system also includes a secondary antenna on the aircraft, the secondary antenna including an array of antenna elements. The antenna system also includes an antenna selection system to control communication of a signal between the aircraft and a target satellite via the primary antenna and the secondary antenna. The antenna selection system switches communication of the signal from the primary antenna to the secondary antenna when a performance characteristic for communication with the target satellite satisfies a threshold due to a position of the aircraft relative to the target satellite.

A computational framework for designing a constellation that includes a plurality of cube satellites (CubeSats) includes an orbit propagation module, a coverage estimation module, a connectivity estimation module and an annealing module. The orbit propagation module receives a plurality of static parameters for the constellation and determines a position vector, a ground track and sub-satellite points for each of the plurality of CubeSats. The coverage estimation module receives the plurality of static parameters for the constellation and estimates Earth coverage for the constellation. The connectivity estimation module receives the plurality of static parameters for the constellation and determines active inter-satellite links (ISL) in the constellation. The annealing module receives input from the orbit propagation module, the coverage estimation module and the connectivity module and employs an annealing algorithm that generates a constellation design.

A computational framework for designing a constellation that includes a plurality of cube satellites (CubeSats) includes an orbit propagation module, a coverage estimation module, a connectivity estimation module and an annealing module. The orbit propagation module receives a plurality of static parameters for the constellation and determines a position vector, a ground track and sub-satellite points for each of the plurality of CubeSats. The coverage estimation module receives the plurality of static parameters for the constellation and estimates Earth coverage for the constellation. The connectivity estimation module receives the plurality of static parameters for the constellation and determines active inter-satellite links (ISL) in the constellation. The annealing module receives input from the orbit propagation module, the coverage estimation module and the connectivity module and employs an annealing algorithm that generates a constellation design.