Motorola Corporation

Raymond Joseph Leopold

Bary R Bertiger

Kenneth M Peterson

Keith Andrew Olds

Brian Michael Daniel

Kenneth Maynard Peterson

Bary Robert Bertiger

Kadathur S Natarajan

Gregory B Vatt

Rodrigo Ibanez-Meier

Theresa C Wang

Jonathan E Hutcheson

Daniel Richard Tayloe

Peter J Armbruster

William F Zancho

Kenneth Lee Sowles

Randy Lee Turcotte

Dennis Paul Diekelman

Isaac N Durboraw, Iii

Steven H Moritz

Peter Alfred Swan

Jeffrey C Morrow

Jeffrey D Laub

Steven Harry Moritz

Theresa Chen Wang

A communication satellite system ( ) is established using one or more satellite constellations ( ). The two or more satellite groups ( ) are connected via long range crosslinks ( ) which provide a communication path between the long range satellites ( ) in the two satellite groups ( ). Each satellite group ( ) comprises long range satellites ( ) and short range satellites ( ) which are interconnected using short range crosslinks ( ). A single antenna on each satellite provides both crosslinks. The long range crosslink ( ) is established using the antenna's main beam and the short range crosslinks ( ) are established using the antenna's sidelobes.

Method and apparatus for using the sidelobe of a long range antenna for a short range communication link

A dynamic beam fill-in system (,) in a cellular communications network (,) having a constellation (,) of satellites (,) in orbit (,) with each satellite (,) having a plurality of antennas (,) configured to form cells (,) upon the surface (,) of the Earth. A first antenna (,) is configured to form a first cell (,) at a first location (,) for a first period (,) of time and at a second location (,) for a second period (,) of time. A second antenna (,) is configured to form a second cell (,) at least partially coincident with the first cell (,) during the first period (,). A third antenna (,) is configured to form a third cell (,) at least partially coincident with the first cell (,) during the second period (,). In the event of failure of the first antenna (,), a computer program (,), in response to a beam-replacement table (,), is configured to deactivate the first antenna (,) and activate the second antenna (,) during the first period (,) and the third antenna (,) during the second period (,).

Dynamic beam fill-in system and method therefor

A geosynchronous satellite system (,) uses crosslinks (,) between geosynchronous satellites (,) which travel along the same ground path (,) or are located within a common orbital slot (,) in order to increase traffic-carrying capacity and decrease signal delays. The geosynchronous satellites (,) can have substantial angles of inclination to provide high quality coverage within a wide range of latitudes (,). In addition, the orbits can be elliptical, resulting in concentrated network capacity in either the northern or southern hemisphere. For co-positioned satellites (,), orbit perturbations are introduced in order to eliminate crosslink blockage caused by intervening satellites (,). Methods for deploying and operating the geosynchronous satellite system enable network capacity to be modified (,) and routing (,), crosslinks (,), and handoffs (,) to be controlled.

Geosynchronous satellite communication system and method

A method and apparatus for rapidly characterizing a communications channel is used to mitigate the effects of the communications channel as present in a received signal. A satellite (,) transmits a data signal (,) and a pilot signal (,). The data signal (,) and the pilot signal (,) are substantially orthogonally polarized. A user terminal (,) receives the orthogonally polarized data signal (,) and pilot signal (,). The user terminal includes a channel information recovery circuit (,) and a channel effects mitigation circuit (,). The channel information recovery circuit (,) characterizes the communications channel by analyzing the pilot signal (,), and then provides the channel information (,) to the channel effects mitigation circuit (,) which then mitigates the effects of the channel.

Method and apparatus for mitigating the effects of a communications channel using polarized signals

A method and apparatus for detecting and tracking spread spectrum signals, such as Global Positioning System (GPS) signals, first obtain precision timing and frequency reference information from a relatively high-power, secondary signal, such as that emanating from a satellite of a low-earth orbit (LEO) satellite communications system, and then use such reference information to perform narrow-band detection of the GPS spread spectrum signal. Accordingly, spread spectrum signals are more efficiently detected and tracked, particularly in environments where they are attenuated by obstacles such as buildings or environmental barriers.

Method and apparatus for detecting spread spectrum signals using a signal from a secondary source

A communication satellite system (100) is established using one or more satellite constellations (110, 120). The two or more satellite groups (110, 120) are connected via long range crosslinks (145) which provide a communication path between the long range satellites (150, 170) in the two satellite groups (110, 120). Each satellite group (110, 120) comprises long range satellites (150, 170) and short range satellites (160, 180) which are interconnected using short range crosslinks (155, 175). A single antenna on each satellite provides both crosslinks. The long range crosslink (145) is established using the antenna's main beam and the short range crosslinks (155, 175) are established using the antenna's sidelobes.

Method and apparatus for using the sidelobe of a long range antenna for

Transmit, receive, and processing functions of a communication satellite are performed by two communication payload satellites. A transmit payload satellite (20) and a receive payload satellite (10) communicate via a crosslink (30,28) which provides the communication path between the two parts of the transmit and receive payload pair (50). The receive payload satellite (10) is optimized to perform substantially all of the receiving and processing functions required in space. The transmit payload satellite (20) is optimized to perform substantially all of the transmitting functions. The optimization process takes into account the location in space for the two separate payloads, where trade-offs are made with respect to electromagnetic signal interference issues, size, weight, power, and complexity.

Transmit and receive payload pair and method for use in communication

A system facilitates global cellular communication by utilizing a gateway satellite (1000) which communicates with low-earth orbiting satellites (10, 20) via signalling links (1001, 1002). Switching is performed in each of the satellites (10, 20) and switching interconnections as well as voice path communications are switched via the gateway satellite (1000). With switching performed in a gateway satellite (1000), the use of a ground-based gateway network (74) is minimized and, in some cases, eliminated.

Satellite communication system and method thereof

A laser transmitter (200, 300) includes a femptosecond pulse forming circuit (214, 308) and an ultra high-speed optical switch (218, 304) which enable the transmitter (200, 300) to generate a modulated pulse stream having pulses with widths of under 200 femptoseconds. The transmitted pulse stream is processed by a laser detector (500), including a wideband optical detector (504) and pulse stretching circuit (506), that regenerates information included in the modulated pulse stream.

Method and apparatus for laser communication through a lossy medium

A satellite communications system employs CDMA multiple access technology. Polarizations are associated with each spreading code to enhance separation between simultaneous users in the absence of perfectly orthogonal spreading codes. A satellite transmitter CDMA encodes(210) and carrier modulates(220) a user or block of users, and then assigns a polarization to the user of block of users. A CDMA reference signal also receives a polarization. A ground receiver (30,40) receives the polarized CDMA signals as transmitted by the satellite. The ground receiver ascertains the polarization of the reference signal and then computes the polarization of the desired polarized CDMA signal. The use of the reference signal negates the effects of the faraday rotation caused by the satellite signal(10,20) passing through the ionosphere.

System for transmitting and receiving polarized CDMA signals and method

A method and apparatus for routing signals through a system (10) which has multiple destination nodes (12, 14) assigns one or more unique carrier frequencies to each destination node (12, 14). When a signal is received (502) by a transceiver (12), the transceiver (12) evaluates (504) the carrier frequency of the signal, and determines (506) to which destination node (12, 14) that carrier frequency is assigned. The determination (506) is made using a table (200) which associates carrier frequencies to destination nodes (12, 14). The table (200) is created (304) and updated by a control facility (20) which distributes (306) the table (200) to the transceivers (12). Once the transceiver (12) determines (506) the destination node (12, 14), the transceiver (12) can route the signal toward that destination node (12, 14).

Method and apparatus for routing signals through a communication system

A constellation (12) of satellites (14) distributed around the earth supports satellite-based communication system (10) involved in global communication of subscriber units (24). Subscriber units (24) may potentially transmit from any location on earth. Some locations such as radio astronomy sites (28) may be interfered with by nearby transmissions from subscriber units (24) or transmissions from satellites (14). Subscriber units (24) located within a potentially interfering proximity to radio astronomy sites are prohibited from transmitting potentially interfering signals by reception of a non-interfering control signal transmitted by a radio astronomy special equipment located at radio astronomy sites. A radio astronomy special equipment (44) repeatedly transmits to a subscriber unit (24) a control signal synchronous with a control signal of a servicing satellite. The radio astronomy special equipment control signal (46), (48), and (54) is compatible with a subscriber unit's communication receiver.

Interference mitigation system for protecting radio astronomy and method

A system for facilitating global cellular/trunked mobile communication is disclosed. This system permits communication with hand held and mobile mounted cellular telephones. The system permits two-way communications anywhere on or above the earth up to a particular height above the earth of several hundred nautical miles. The system employs a number of low-earth orbiting satellites moving about the earth in orbit. Links are provided from the satellites directly to the users and via the public switched telephone network to other users. The satellites are interconnected via links in a ring structure surrounding the earth. Switching is performed by each of the satellites. In addition, each of the satellites hands off a call as it moves out of the range of a particular user.

Satellite cellular telephone and data communication system

A cellular communication system projects multiple cells throughout a user area. Subscriber units (24) encounter multiple cells as they roam through the user area or as the cells migrate past the subscriber unit (24). When a subscriber unit (24) encounters the fringe area of a cell it maintains contact with the system by selecting and transitioning to a target cell. The subscriber unit (24) performs an analysis using Doppler data of the location, proximity, and expected duration of exposure to candidate target cells. The subscriber unit (24) selects a target cell based on these factors.

Method and system for intelligent cell selection using doppler data in

A cellular communication system projects multiple cells throughout a user area. Subscriber units (24) encounter multiple cells as they roam through the user area or as the cells migrate past the subscriber unit (24). When a subscriber unit (24) encounters the fringe area of a cell it must select and transition to a target cell to maintain contact with the system. The subscriber unit (24) performs an analysis of the location, proximity, and expected duration of exposure of candidate target cells using location data transmitted by control channels located in the candidate cells. The subscriber unit (24) then selects a target cell based on these factors.

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Tempe, AZ, United States of America

Raymond Joseph Leopold