Embodiments provide in-flight configuration of satellite pathways to flexibly service terra-link and cross-link traffic in a constellation of non-processed satellites, for example, to facilitate flexible forward-channel and return-channel capacity in a satellite communications system. For example, each satellite in the constellation can include one or more dynamically configurable pathway, and switching and/or beamforming can be used to configure each pathway to be a forward-channel pathway or a return-channel pathway in each of a number of timeslots according to a pathway configuration schedule. At least some of the pathways can be further selectively configured, in each timeslot, to carry "terra-link" traffic to and/or from terrestrial terminals and "cross-link" traffic to and/or from one or more other satellites of the constellation.

Flexible capacity satellite constellation

Beamformed directional wireless communications are described that provide for spatial re-use that allows multiple pairs of peer-to-peer (P2P) links to communicate simultaneously over the same channel in the same spatial vicinity, without contention, and independent of centralized control. The spatial re-use improves network throughput by sharing spectrum resource among multiple links. Beamformed training includes obtaining best sector and least sector information by all stations. Prior to performing an independent P2P communication, antenna array sector information is checked, to assure that the sector to be selected is not impinging interference on other P2P interactions, then a request is made to a target station. The target station also refers to its sector information, and if no conflict is found it accepts and acknowledges the request, upon which it receives the P2P communication.

Method and system for P2P communications and decentralized spatial sharing in wireless networks with directional transmissions

A communication platform such as a spacecraft, airborne platform, or terrestrial line of site wireless platform is provided with adaptive digital beamforming. The satellite digitizes a full spectrum allocation for digital channelization. A channelization engine can determine a particular user or user group associated with an uplink signal. In this manner, the communication platform can apply different processing based on the user or group associated with a signal. For example, the communication platform receives uplink signals associated with a first user group and a second user group in one embodiment. The platform dynamically generates one or more spot beams for the first user group and the second group. The platform discriminates the uplink signals to apply frequency hopping for the downlink frequency channel assignments to the second user group while the downlink frequency channel assignments for the first user group remain fixed.

Protected Overlay Of Assigned Frequency Channels

Systems and methods are provided for receiver nonlinearity estimation and cancellation. During processing of received radio frequency (RF) signals, it may be determined when one or more other signals, different from the received RF signals, cause nonlinearity affecting processing of the RF signals, and one or more cancellation adjustments may be applied during processing of the RF signals, for mitigating effects of the nonlinearity. Determining the one or more cancellation adjustments may be based on narrowband (NB) estimation of the effects of the nonlinearity, and the one or more cancellation adjustments may be configured as wideband (WB) corrections. The NB estimation may be applied based on channelization of the received RF signals. The NB estimation may comprise generating reference nonlinearity information relating to the one or more other signals, and generating, based on the reference nonlinearity information, control data for configuring the one or more cancellation adjustments.

Receiver nonlinearity estimation and cancellation

Disclosed is a demodulation method to be used by an apparatus receiving a data packet transmitted in wired and wireless communications to recover data from a received signal. The apparatus receiving the data packet may recover or synchronize a symbol timing that is used to recover the data, and a demodulator included in the apparatus receiving the data packet may determine the symbol timing through different methods based on a length of a burst included in the data packet.

Modem performing modulation or demodulation based on length of burst in data packet, and method performed by the modem

An apparatus and digital signal processing means are disclosed for excision of co-channel interference from signals received in crowded or hostile environments using spatial/polarization diverse arrays, which reliably and rapidly identifies signals with transmitted features that are almost-periodic over known framing intervals, and exploits those features to develop diversity combining weights that substantively extract those signals from that environment, based on differing diversity signature, timing offset, and carrier offset of those signals. In one embodiment, the signal identification and extraction is performed in an applique that can be implemented without coordination with an actual radio transceiver.

Interference-excising diversity receiver adaptation using frame syn- chronous signal features and attributes

An apparatus and digital signal processing means are disclosed for excision of co-channel interference from signals received in crowded or hostile environments using spatial/polarization diverse arrays, which reliably and rapidly identifies communication signals with transmitted features that are self-coherent over known framing intervals due to known attributes of the communication network, and exploits those features to develop diversity combining weights that substantively excise that co-channel interference from those communication signals, based on differing diversity signature, timing offset, and carrier offset between the network signals and the co-channel interferes In one embodiment, the co-channel interference excision is performed in an applique that can be implemented without coordination with a network transceiver

Brian G. Agee

Papers

Interference-excising diversity receiver adaptation using frame syn- chronous signal features and attributes

Adaptive Excision of Co-Channel Interference Using Network Self-Coherence Features