Abstract: A node in a hybrid wireless link includes a free space optical (FSO) terminal and a radio frequency (RF) terminal. The FSO terminal is configured to transmit data over an FSO link, and the RF terminal is configured to transmit data over a free space RF link. The node also includes a switch/controller coupled to the FSO terminal and the RF terminal. The switch/controller is configured to receive data and determine at the data link layer whether to transmit data frames of the data over the FSO link, the RF link, or both. The determination is based on the content of the data frames, and, once the determination is made, the switch/controller steers the data frames to the FSO terminal, the RF terminal, or both. In some embodiments, the switch/controller makes the determination at the network layer.

Abstract: A broadband wireless system includes a plurality of spaced-apart ground stations for transmitting and receiving signals to and from a respective plurality of aircraft. Each of the plurality of ground stations may include a ground station transceiver including a ground station antenna carried by a mechanically steered platform, a ground station router in communication with the ground station transceiver, and a ground station beacon transceiver in communication with the ground station router. An aircraft transceiver may be carried by each of the plurality of aircraft to be positioned in communication with one of the plurality of ground stations. The aircraft transceiver may include an aircraft antenna mounted to the aircraft, an aircraft transceiver carried by the aircraft and in communication with the aircraft antenna, and an aircraft radio transceiver carried by the aircraft and in communication with the aircraft beacon transceiver.

Abstract: A free space laser communication system uses subcarrier multiplexing to prepare multiple data communication channels for impressing onto a laser carrier. Sending and receiving terminals mutually track to insure acquisition of the transmitted data signals.

Abstract: A system for despreading a spread spectrum signal includes at least one receiver for capturing a plurality of snapshots of the signal and a processing device for constructing a confidence vector from at least two of the plurality of snapshots. The processing device is operable to generate a first estimated spreading sequence of the signal, and to correlate the first estimated spreading sequence and the confidence vector to generate a second spreading sequence for despreading the signal.

Abstract: A system for despreading a spread spectrum signal includes at least one receiver for capturing a plurality of snapshots of the signal and a processing device for constructing a confidence vector from at least two of the plurality of snapshots. The processing device is operable to generate a first estimated spreading sequence of the signal, and to correlate the first estimated spreading sequence and the confidence vector to generate a second spreading sequence for despreading the signal.

Abstract: A trellis coded modulation system for use with a plurality of QAM modes that allows a choice of modulation scheme tailored to a communication channel. The system comprises an encoder and a decoder. The decoder uses input and output look-up tables that allow the use of a single decoder/encoder arrangement comprising a Viterbi decoder and a convolutional encoder to map trellis coded modulation to/from multiple modulation constellations. The size of the look-up tables used in the decoder is minimized because recognizable sequences (6 bits) are passed to the Viterbi decoder. The input look-up table provides minimal information about which region the symbol was found. The output look-up table processes the resulting information appropriately.

Abstract: An architecture for a self-selective multi-rate transmitter that processes variable input rate data using a plurality of single input, multiple output interleavers. The transmitter, using a multitude of modulation formats, transmits the data at a constant symbol rate without a priori knowledge of the input rate. The transmitter employs a modulator that automatically selects between a multitude of signal constellations, depending on the rate of the source data to be transmitted. The modulator transmits data from various sources, each with an independent data rate. The modulator performs data formatting, forward error correction encoding, modulation onto an intermediate frequency, frequency conversion to a transmit radio frequency, and amplification with automatic gain control.