Methods, systems, and devices for wireless communications are described. A base station may transmit repetitions of a tracking reference signal to a user equipment (UE). The UE may determine a Doppler frequency for the downlink channel by measuring the repetitions of the tracking reference signal. The UE may transmit an indication of the downlink Doppler frequency to the base station. The base station may determine the uplink Doppler frequency based on the downlink Doppler frequency. The base station may use the uplink Doppler frequency to select an uplink demodulation reference signal (DMRS) configuration for the UE.

Methods, systems, and devices for wireless communications are described. A base station may transmit repetitions of a tracking reference signal to a user equipment (UE). The UE may determine a Doppler frequency for the downlink channel by measuring the repetitions of the tracking reference signal. The UE may transmit an indication of the downlink Doppler frequency to the base station. The base station may determine the uplink Doppler frequency based on the downlink Doppler frequency. The base station may use the uplink Doppler frequency to select an uplink demodulation reference signal (DMRS) configuration for the UE.

The present invention provides a method of performing by a UE device a random access attempt in a communication system comprising at least one non-terrestrial transmission station, the method comprising receiving reference signals transmitted by the non-terrestrial transmission station; determining from the received reference signals a trip time between the UE device and the non-terrestrial transmission station; and using the trip time to control the random access attempt.

The present invention provides a method of performing by a UE device a random access attempt in a communication system comprising at least one non-terrestrial transmission station, the method comprising receiving reference signals transmitted by the non-terrestrial transmission station; determining from the received reference signals a trip time between the UE device and the non-terrestrial transmission station; and using the trip time to control the random access attempt.

A method and system for Air-To-Ground communications allowing integration of the aircraft communication with a terrestrial cellular communications network. The solution is carried out in the aircraft so any existing standard terrestrial cellular communication network may be used without requiring any modification. The constraints due to the special aircraft conditions (speed and height) are efficiently solved, allowing broad interoperability with the cellular communications network, satisfying the increasing high speed data demand. Specifically, in order to solve the handover constraints the aircraft antenna will create at least two radiation patterns: one for maintaining the current connection with the serving base station and another one or more to search the next suitable best station for handover.

A method and system for Air-To-Ground communications allowing integration of the aircraft communication with a terrestrial cellular communications network. The solution is carried out in the aircraft so any existing standard terrestrial cellular communication network may be used without requiring any modification. The constraints due to the special aircraft conditions (speed and height) are efficiently solved, allowing broad interoperability with the cellular communications network, satisfying the increasing high speed data demand. Specifically, in order to solve the handover constraints the aircraft antenna will create at least two radiation patterns: one for maintaining the current connection with the serving base station and another one or more to search the next suitable best station for handover.

A multiple-access transceiver handles communications with mobile stations in environments that exceed mobile station design assumptions without necessarily requiring modifications to the mobile stations. One such environment is in Earth orbit. The multiple-access transceiver is adapted to close communications with mobile stations while exceeding mobile station design assumptions, such as greater distance, greater relative motion and/or other conditions commonly found where functionality of a terrestrial transceiver is to be performed by an orbital transceiver. The orbital transceiver might include a data parser that parses a frame data structure, a signal timing module that adjusts timing based on orbit to terrestrial propagation delays, frequency shifters and a programmable radio capable of communicating from the Earth orbit that uses a multiple-access protocol such that the communication is compatible with, or appears to the terrestrial mobile station to be, communication between a terrestrial cellular base station and the terrestrial mobile station.

A multiple-access transceiver handles communications with mobile stations in environments that exceed mobile station design assumptions without necessarily requiring modifications to the mobile stations. One such environment is in Earth orbit. The multiple-access transceiver is adapted to close communications with mobile stations while exceeding mobile station design assumptions, such as greater distance, greater relative motion and/or other conditions commonly found where functionality of a terrestrial transceiver is to be performed by an orbital transceiver. The orbital transceiver might include a data parser that parses a frame data structure, a signal timing module that adjusts timing based on orbit to terrestrial propagation delays, frequency shifters and a programmable radio capable of communicating from the Earth orbit that uses a multiple-access protocol such that the communication is compatible with, or appears to the terrestrial mobile station to be, communication between a terrestrial cellular base station and the terrestrial mobile station.

A general-purpose integrated circuit capable of scaling to meet the requirements of a beamforming system for a wide range of applications and benefit from economies of scale is disclosed. The integrated circuit includes a delay and phase correcting engine in order to reference the incoming data to a common array center and steering direction. It also includes a frequency channelization engine to perform phase-shift beamforming tasks effectively and/or frequency channelize the output data stream. A flexible reconfigurable routing logic can be included, which allows a multiplicity of operation modes, and generates a multiplicity of linear combinations of the input and internally generated data streams.

A general-purpose integrated circuit capable of scaling to meet the requirements of a beamforming system for a wide range of applications and benefit from economies of scale is disclosed. The integrated circuit includes a delay and phase correcting engine in order to reference the incoming data to a common array center and steering direction. It also includes a frequency channelization engine to perform phase-shift beamforming tasks effectively and/or frequency channelize the output data stream. A flexible reconfigurable routing logic can be included, which allows a multiplicity of operation modes, and generates a multiplicity of linear combinations of the input and internally generated data streams.