A satellite communication system leverages the carrier offset detection capability of the demodulator contained in an on-board modem of M&C channel. The modem detects the frequency error Δf, introduced in the signal path from the output of the base station at ground to the output of baseband conversion on the satellite, by analyzing the baseband signal at the baseband conversion to estimate the received carrier f′c and subtracting it the from the expected frequency (fc).

Methods and transceivers transmit communication frames that comprise a sequence of N symbols, ensuing payload header symbols, and ensuing payload message symbols. The sequence of N symbols encodes information according to signal-to-noise ratio associated with the communication frame.

A system and method are disclosed for synchronizing timing for a terminal in a satellite communication system. Upon detecting a service interruption, first timing markers are extrapolated from timing information received prior to the service interruption. Second timing markers are also extrapolated from timing information received subsequent to the service interruption. Timing for the terminal is then synchronized with the gateway based on a timing difference between the first timing markers and the second timing markers.

A method includes, in a transceiver (24), receiving from a repeater (32) a received signal, which includes a desired signal for reception and an undesired replica of a transmitted signal that was transmitted from the transceiver and retransmitted by the repeater. A local copy of the transmitted signal is generated in the transceiver. A filter response that, when applied to the transmitted signal before transmission, compensates for a difference in spectral response between the local copy and the undesired replica, is estimated in the transceiver. The undesired replica of the transmitted signal, which is received in the received signal, is matched with the local copy of the transmitted signal, by at least pre-filtering the transmitted signal before transmission with the estimated filter response. Interference caused by the undesired replica to the desired signal is canceled, by combining the local copy and the received signal.

A satellite communication system comprises a satellite configured to provide a plurality of spot beams adapted for communication using time domain beam hopping to switch throughput among spot beams of the plurality of spot beams. The plurality of spot beams includes a first spot beam that illuminates and communicates with a first gateway and a first set of subscriber terminals. The satellite is configured to implement a beam hopping plan that during a hopping period provides throughput to the first spot beam for an aggregated time duration based on bandwidth assignments to the first gateway and the first set of subscriber terminals.

Systems and methods are described for robust scheduling of beam switching patterns in satellite communications systems. Embodiments operate in context of a hub-spoke satellite communications architecture having a number of gateway terminals servicing large numbers of user terminals over a number of spot beams. The satellite includes switching subsystems that distribute capacity to the user beams from multiple of the gateway terminals in a shared manner according to a beam group switching pattern. The beam group switching pattern is robustly formulated to continue distributing capacity during gateway outages (e.g., when one or two gateway terminals are temporarily non-operational due to rain fade, equipment failure, etc.). For example, the beam group switching pattern can be formulated to minimize worst-case degradation of capacity across user beams, to prioritize certain beams or beam groups, etc.

Mitigation of satellite interference is contemplated. The mitigation may include processing satellite transmissions to remove interferences based on an amount of signal overlap, such as to facilitate mitigating interferences resulting from satellite spacing and/or ground antenna dish size.

An unmanned mobile communication station is adapted for location in a marine environment and includes a platform adapted for flotation or is semi-submersible, a communication node for sending and receiving wireless signals, a power system for energizing said communication node, a data center, at least one sensor for detecting the geolocation of the platform; and a processor for receiving signals from said sensors and controlling communication to and from communication nodes wherein embodiments include both autonomous and remote controlled navigation and propulsion systems.

According to an example aspect of the present invention, there is provided a method comprising: receiving, from a network node, before entering a power saving state, an indication of a dependency between frequencies and time instances; identifying at least one frequency based on the indicated dependency and a moment of time; and selecting a cell utilizing the identified at least one frequency.

An integrated analog to digital converting and digital to analog converting (ADDA) RF transceiver for satellite applications, configured to replace conventional analog RF down and up conversion circuitry. The ADDA RF transceiver includes one of more ADCs, DSPs, and DACs, all on a single ASIC. Further, the circuitry is to be radiation tolerant for high availability and reliability in the ionizing radiation environment present in the space environment.