Lockheed Martin Corporation

Xiangdong Liu

Dilip Shyamsundar Gokhale

Muthuthamby Sreetharan

Suresh K Iyer

Piya Seth Bhaskar

Joshua Schachter

Systems and methods for communication in 4G and 5G broadband satellite networks are provided. The disclosed methods include Global Navigation Satellite System (GNSS)-independent methods, and GNSS assisted methods that do not require transmission of satellite ephemeris information from a base station to user equipment.

Random access for broadband 4G and 5G over satellite

A satellite communication system includes a satellite, satellite base station (eNodeB or gNodeB) and a user equipment (UE). The satellite provides a number of satellite beams, and each satellite beam includes multiple cells. The base station communicates with the UE via a satellite using a narrowband internet of things (NB-IoT) waveform and an enhanced protocol. In particular, the base station and UE perform carrier aggregation by adding and/or deleting carriers in a cell, and the base station and UE perform a higher-order modulation and coding scheme (MCS) processing to support high data rates for user data transport.

Achieving higher data rate on NB-IoT over satellite

Provided herein are various improvements to communication systems and satellite-carried communications. In one example, a method provides communication coverage for at least an endpoint device within a cell. The method includes detecting access preamble communications transferred by the endpoint device during a random access slot of a base station by at least applying a selected quantity of successive sets of processing windows in accordance with a round-trip minimum communication delay expected between the base station and the cell, with each of the successive sets shifted in time by a selected duration. The method also includes determining a round-trip differential communication delay for the endpoint device based on which of the successive sets corresponds to detection of symbol groups of the access preamble communications, and handling return communications transferred by the endpoint device based at least on a combination of the round-trip minimum communication delay and the round-trip differential communication delay.

Random-access endpoint communication handling for satellite-transported communication links

A satellite communication system includes a satellite, a satellite base station, and a user device. The satellite supports a number of satellite beams. Each satellite beam includes a number of cells. The satellite base station can communicate with the satellite via a feeder link. The user device is in communication with the satellite and the satellite base station. The user device can select a cell that covers a location of the user device based on a cell contour and a quality of a downlink signal received from the satellite base station. The satellite communication system can be operated by using LTE and/or NB-IoT standards, protocols, and/or waveforms.

Narrow-band IoT and LTE over satellite

A method for of communication in a satellite LTE network by a satellite base station includes transmitting to a terminal device in a satellite beam of the satellite base station a frame having embedded timing information. The timing information includes a lowest delay time associated with the satellite beam. An uplink acquisition message is received from the terminal device. The uplink acquisition message is received with a first timing advance (TA) value estimated by the terminal device based on the lowest delay time. An arrival time associated with the uplink acquisition message is estimated, and a second TA value is determined based on the estimated arrival time. The terminal device uses the sum of first TA and second TA to adjust its timing in subsequent transmissions.

Random access for LTE over satellite

A method for resource allocation in a multi-beam satellite LTE network includes determining, via a communication processor, a per sub-frame resource block (RB) threshold value on a per-beam and per-LTE carrier basis, based on a total transmission power and shared power amplifiers available to multiple beams of a space vehicle while ensuring that power amplifiers operate in a linear amplification region. The method further includes communicating the LTE per subframe RB threshold value to a downlink LTE scheduler function within the eNode-B to ensure that the count of subframe level RB allocations is less than the determined LTE per subframe RB threshold value.

Power usage-aware spectral resource allocation in a satellite long term evolution (LTE) communication system

A method, a member satellite, and a tangible machine-readable medium are disclosed. An inter-satellite link subsystemmay maintain a fixed communication link between the member satellite and a partner satellite of the medium earth orbit centric satellite constellation in a regular, wraparound symmetric, spatially dimensional network. A terrestrial linking subsystemmay create a terrestrial link to a ground terminal.

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Boyds, MD, United States of America

Xiangdong Liu