Atc Technologies, Inc.

Amsc Subsidiary Corporation

Other

Motient Services Inc.

Gary G Churan

Santanu Dutta

Peter Dimitrios Karabinis

Dunmin Zheng

William R Tisdale

David J Ross

Michael K Ward

Michael E Threadgill

Serge Nguyen

Edward J Modzelesky

Charles Kittiver

Charles H Biegel

The present disclosure describes the concept of operations and the medium access control protocols of a wireless communication system using code-division multiple access with interference avoidance (CDMA-IA) as its physical layer. The system can dynamically share a common band with other networks without a central radio resource controller. In one embodiment, the wireless communication system includes a plurality of radio nodes forming a wireless mesh network, wherein the pairs of radio nodes use, individually optimized, time division duplexing. At least one radio node includes a software-defined radio, a memory, and an electronic processor. The electronic processor is configured to control the software-defined radio to transmit a pilot signal and share various state information with the other nodes of the network. The shared information includes local spectrum occupancy and node connectivity sets. The pervasive sharing of spectrum occupancy among all nodes enables the usage of the shared band to be maximized.

CDMA-IA network concept of operations and media access control (MAC) layer

Devices, methods, and systems for uplink synchronization in time division multiple access (TDMA) satellite network. In one embodiment, an earth-based satellite terminal is configured to communicate with a satellite hub through a satellite using the TDMA communication protocol. The earth-based satellite terminal is configured to determine its own location, a location of the satellite, estimate a distance between the location of the terminal and the location of the satellite, determine a Coarse Timing Advance based on the distance that is estimated, and transmit data to the satellite based on the Coarse Timing Advance and the TDMA communication protocol. The Coarse Timing Advance may allow uplink TDMA communication without a preamble transmission on a random access channel, the preamble transmission being required in many conventional systems.

Devices, methods, and systems for uplink synchronization in time division multiple access (TDMA) satellite network

The present disclosure includes wireless communication systems with code-division multiple access with interference avoidance (CDMA-IA). In one embodiment, the wireless communication system includes a plurality of transmitters and a plurality of receivers. At least one transmitter of the plurality of transmitters is configured to detect unoccupied segments of spectrum occupancy of interference at one of the plurality of receivers, and spread power of a transmitted signal non-uniformly across a channel bandwidth that is much wider than an information bandwidth of the transmitted signal using a plurality of non-contiguous spectral segments that correspond to the unoccupied segments of the spectrum occupancy of the interference at the one of the plurality of receivers. At least one receiver of the plurality of receivers is configured to perform a demodulation process by coherently integrating the power of the transmitted signal over the plurality of non-contiguous spectral segments.

Wireless communication systems with code-division multiple access and interference avoidance

First radio signals are received by a first satellite, the received first radio signals including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the first source and an interfering signal transmitted from a second source using the frequency assigned to the first source. The first radio signals are combined based on a first performance criterion to generate a first output signal. Second radio signals are received by a second satellite, the received second radio signals including a measure of the desired signal. The second radio signals are combined based on a second performance criterion to produce a second output signal. The first and second output signals are combined to generate an estimate of the desired satellite uplink signal.

Additional intra-and/or inter-system interference reducing systems and methods for satellite communications systems

A communications system includes a space-based network (SBN) including a plurality of spotbeams using a first set of frequencies and an ancillary terrestrial network (ATN) including a plurality of base stations using a second set of radio frequencies. In a coverage zone of a given spot beam wherein the SBN and the ATN use at least one frequency from the first and second sets of frequencies in common, the SBN uses a narrower bandwidth than the ATN on both forward and return links, the ATN employs frequency spreading on at least its return link communications, the SBN employs spatial beam nulling directed toward at least one ancillary terrestrial component (ATC) of the ATN, the SBN employs forward link margin control, the ATN employs return link power control, the SBN employs return link power control and base stations of the ATN provide isolation in the direction of at least one satellite of the SBN. Using such a combination of measures, the ATN and the SBN may support completely or partially overlapping use of the first and second sets of radio frequencies.

Systems, methods and devices for overlaid operations of satellite and terrestrial wireless communications systems

Methods of operating a transceiver including an antenna having a plurality of antenna feed elements include providing a plurality of gain constraint values associated with respective ones of the plurality of geographic constraint points within a geographic region, selecting initial phase constraint values associated with respective ones of the gain constraint values, generating antenna feed element weights based on the gain constraint values and based on the initial phase constraint values, and determining system response values in response to the antenna feed element weights. Phases of the system response values are compared to the initial phase constraint values, and an antenna beam is formed from the antenna to the geographic region using the antenna feed element weights in response to the comparison of the phases of the system response values to the initial phase constraint values. Related systems and devices are also disclosed.

Antenna beam forming systems, methods and devices using phase adjusted least squares beam forming

A processor for use in a satellite communications system includes a selector that is configured to select a subset of a plurality of spatially diverse satellite signals based upon a location of a radioterminal. The processor further includes a signal processor that is configured to detect a return-link transmission from the radioterminal responsive to the selected subset of the spatially diverse satellite signals. The respective spatially diverse satellite signals may include respective signals corresponding to respective antenna elements of a satellite. The selector and the signal processor may be ground based.

Satellite communications systems and methods using radiotelephone

Satellite communications systems and methods using radiotelephone location-based beamforming

A space-based component, such as a satellite, is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency, and to transmit wireless communications to the radiotelephones over a downlink radiotelephone frequency. An ancillary terrestrial network, that may include one or more ancillary terrestrial components, is configured to transmit wireless communications to, and receive wireless communications from, the radiotelephones over the uplink satellite radiotelephone frequency in a time-division duplex mode. An interference reducer is configured to reduce interference from the wireless communications that are received by the space-based component from the second radiotelephone and/or from the ancillary terrestrial network over the uplink satellite radiotelephone frequency, using the wireless communications that are transmitted by the ancillary terrestrial to, and/or received by the ancillary terrestrial network from, the second radiotelephone over the uplink satellite radiotelephone frequency.

Systems and methods for terrestrial reuse of cellular satellite frequency spectrum in a time-division duplex and/or frequency-division duplex mode

Beamforming methods for operating a transceiver including an antenna having a plurality of antenna feed elements include defining a plurality of real valued antenna gain constraint values associated with a plurality of geographic constraint points within a geographic region, and generating complex valued antenna feed element weights that result in complex antenna gain values at the geographic constraint points based on the corresponding real valued antenna gain constraint values. An antenna beam is formed from the antenna to the geographic region using the complex valued antenna feed element weights, and information is transmitted over the antenna beam.

Antenna beam forming systems/methods using unconstrained phase response

A signal is received at a component of the wireless CDMA communications system, such as a base station or satellite gateway. A plurality of data sets is generated from the received signal, respective ones of the plurality of data sets corresponding to respective access probes received, for example, over the reverse access channel (R-ACH) or reverse enhanced access channel (R-EACH). At least some of the plurality of data sets are jointly decoded to recover an access probe payload.

Methods, apparatus and computer program products for joint decoding of access probes in a CDMA communications system

An uplink signal transmitted by a terminal is received by a satellite wireless communications system. The uplink signal includes a known information element, e.g., a reverse access channel (R-ACH) preamble, spread according to a spreading code specific to a component of a satellite wireless communications system, e.g., a pseudonoise (PN) sequence associated with a satellite beam. A correlation of the received uplink signal with the spreading code over a range of time shifts is determined. The known information element is detected from the determined correlation. The satellite wireless communications system is synchronized with the terminal responsive to detection of the known information element. For example, a delay may be assigned to a receiver of the satellite wireless communications system responsive to detection of the known information element.

Growing community of inventors

Annadale, VA, United States of America

Gary G Churan