Aeroastro, Inc.

Higherground, Inc.

Comtech Mobile Datacom Corporation

Other

Immersion Corporation

Ihi Aerospace Co., Ltd.

Orbcomm Sens, LLC

Scott A McDermott

Richard David Fleeter

John Eric Hanson

Raymond G Zenick, Jr

Shmuel Shaffer

Bruce Leonard McKinley

Mark Evan Russell

Luis Jordan

David Daugherty

Timothy Reed Cooper

James F Stafford

Robert F Cohen

R Clayton Smith

Thomas Vaneck

Robert A Summers

David M Tumey

Kinji Mori

Hiroyuki Yashiro

David Goldstein

Paul Gloyer

Jonathon Miller

David Ziers

Simon Morris Shand Weiss

William F Seng

Leif Eric Aamot

Er-Hsien Fu

In one embodiment, a communicating device (e.g., either a ground station server or a particular distributed module of a satellite communication system) mitigates congestion on a particular return communication path via an intermediate satellite from the plurality of distributed modules to the ground station server. In particular, in response to determining that the level of congestion is above a threshold, then the communication device mitigates the congestion by, e.g., one or both of either a) determining an uncongested return communication path from a particular distributed module to the ground station server, ensuring that the uncongested return communication path would not interfere with any unintended receiver, and then causing the particular distributed module to use the uncongested return communication path, and b) enforcing one or more communication restrictions on a utilized return communication path to reduce the effect of a communication on the overall congestion of the utilized return communication path.

Return path congestion mitigation for satellite communications

A communications protocol in accordance with one exemplary embodiment uses information from GPS satellites to synchronize the phases of transmitters, and aligns the phase with a spreading code used to de-spread the received signals at, for example, a ground station.

Synchronized CPDMA (code phase division multiple access)

In one embodiment, a ground station server of a satellite communication system mitigates congestion on a particular forward communication path via an intermediate satellite from the ground station server to a plurality of distributed modules. In particular, in response to determining that the level of congestion is above a threshold, then the ground station server mitigates the congestion by, e.g., determining uncongested forward communication paths, scheduling a sufficient amount of communication over the uncongested forward communication paths to alleviate congestion on the particular forward communication path without congesting the one or more uncongested forward communication paths, transmitting instructions on the particular forward communication path to corresponding modules of the plurality of distributed modules, the instructions causing the corresponding modules to use a respective uncongested forward communication path, and communicating to the corresponding modules on their respective uncongested forward communication path.

Forward path congestion mitigation for satellite communications

A technique for spectral widening in a communication system may divide respective symbols of a block of symbols into symbol pieces of shorter duration than a symbol. The symbol pieces may be scrambled. The resulting scrambled symbol pieces may optionally be further spread using direct-sequence spreading prior to transmission. Error-control coding may also be used prior to dividing the symbols into symbol pieces and scrambling the symbol pieces. Additionally, the number of symbol pieces per symbol may be adjustable, based on channel characteristics, performance, or both.

Breaking up symbols for spectral widening

Techniques for compensating for frequency offset of a frequency used in a translation of a signal from a first band to a second band may include using a frequency reference signal located in a different band from an information-bearing signal, where the different band may be a guard band. The frequency reference signal may be offset from a particular frequency, which may be a center frequency, of the information-bearing signal by a known amount. The frequency reference signal may be received by the transmitting station, a frequency offset may be derived, and the frequency offset may be used to pre-compensate further transmitted signals. At another station, the received frequency reference signal may be used to lock a local oscillator for demodulation and/or transmission of the information-bearing signal based on the known offset of the frequency reference signal from the frequency of the information-bearing signal.

Frequency compensation techniques and systems

A transmitter transmits a signal to a receiver using spread spectrum signals. The transmitter generates a respective signal. The transmitter separates the respective signal into multiple predefined portions, wherein each predefined portion is below a noise floor. The transmitter transmits at least a plurality of the predefined portions of the respective signal at discrete bandwidth intervals in accordance with a spread spectrum signal splitting technique. The discrete bandwidth intervals are portions of spectrum that are available for transmission. The receiver receives at least a plurality of the multiple predefined portions of the respective signal at the discrete bandwidth intervals. The receiver reconstructs the respective signal using at least a plurality of the predefined portions in accordance with the spread spectrum signal splitting technique.

System and methods for dynamic spread spectrum usage

A communication system is provided that allows the use of low-cost, low-power remote terminal units that communicate substantially asynchronously and independently to a base station. To minimize cost and complexity, the remote terminal units are configured similarly, including the use of substantially identical transmission schemes, such as a common Direct Sequence Spread Spectrum (DSSS) code. To minimize collisions among transmissions, the communication system is designed to use a high-gain antenna with a limited field of view, to limit the number of cotemporaneous, or overlapping transmissions that are received at the base station. To cover a wide area, the limited field of view is swept across the area of coverage. To overcome potential losses caused by collisions, the remote terminal units are configured to repeat transmissions; to minimize repeated collisions, the repeat interval and/or duration is randomized.

Low-cost satellite communication system

A receiving system dynamically searches the communications band for transmissions of messages having the same nominal communications parameters, including the use of the same spreading code, but having potentially different specific frequencies and code-phases. The receiver, which is independent of the transmitters, samples the communications band at each code-phase of the spreading code over a span of downconverted transmission frequencies. When a message element is detected at a particular code-phase and frequency, it is forwarded to a demodulator that demodulates the message and sends it to its intended destination. In a preferred embodiment, a progressive Fourier Transform is used to incrementally determine the power level at each successive code-phase at a given frequency, thereby substantially reducing the time required to search for transmissions at each discrete code-phase.

Spread-spectrum receiver with progressive fourier transform

One or more frame slots to each transceiver are allocated for communication within each message cycle. The number of frame slots allocated can be dynamically adjusted to accommodate variable traffic loads per transceiver, and an offset of the frame slots within the message cycle is preferably predefined to provide a uniform distribution among the transceivers. The design of the transceiver is independent of the particular application, having at least one programmable parameter that controls the number of frame slots allocated within the message cycle. By controlling the number of frame slots allocated to a transceiver, the amount of inactive time, and hence battery life, can be controlled. When a conflict occurs among multiple transceivers having pending messages at the same frame slot, the allocation of the frame slot to a transceiver is based at least in part on the resultant lag time to each transceiver.

Time slot synchronized, flexible bandwidth communication system

A spacecraft architecture and accompanying standard allows for the creation of a spacecraft using an assortment of modules that comply with the standard. The standard preferably includes both mechanical and electrical compatibility criteria. To assure physical/mechanical compatibility, the structure of each module is constrained to be compatible with any other compatible module. To minimize the interference among modules, the extent of each module in select dimensions is also constrained. To assure functional compatibility, a common communication format is used to interface with each module, and each public-function module is configured to respond to requests for function capabilities that it can provide to other functions. Each module is preferably designed to provide structural support to the assemblage of modules, and an anchor module is provided or defined for supporting the entire assemblage and coupling the assemblage to other structures, such as a launch vehicle.

Modular spacecraft design architecture

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Washington, DC, United States of America

Scott A McDermott