Abstract: A TCS (200) and procedure (400) for identifying an unidentified class as a class of a group of classes includes a new tree-structured classifier (208) and training processor (204). Unidentified feature vectors representing an unidentified class are combined with predetermined models to compute a score for each of the unidentified feature vectors. Based on the scores for each of the unidentified feature vectors, an association is made with the predetermined models to identify the unidentified class. Predetermined models are created using a training procedure (300) for predetermined feature vectors associated therewith. A procedure (400) for identifying an unidentified class as a class of a group of classes is useful when determining access privileges to a device or system.

Abstract: A geosynchronous satellite system (10) uses crosslinks (30) between geosynchronous satellites (16) which travel along the same ground path (18) or are located within a common orbital slot (32) in order to increase traffic-carrying capacity and decrease signal delays. The geosynchronous satellites (16) can have substantial angles of inclination to provide high quality coverage within a wide range of latitudes (40, 42). In addition, the orbits can be elliptical, resulting in concentrated network capacity in either the northern or southern hemisphere. For co-positioned satellites (171-174), orbit perturbations are introduced in order to eliminate crosslink blockage caused by intervening satellites (172, 173). Methods for deploying and operating the geosynchronous satellite system enable network capacity to be modified (708) and routing (804), crosslinks (1008), and handoffs (908) to be controlled.

Abstract: System efficiently communicates a perceptually encoded speech spectrum signal from a transmitter to a receiver. The transmitter includes a speech analyzer which accepts a speech signal input and generates a parameterized speech signal. The transmitter also includes a vector quantizer for generating the perceptually encoded speech spectrum signal from the parameterized speech signal. The receiver decodes the perceptually encoded speech spectrum signal to produce decoded spectral parameters to further produce a synthetic speech output. The vector quantizer performs a method for partitioning a vector quantizer (VQ) codebook to produce perceptually organized sub-codebooks. The vector quantizer performs a second method for quantizing a vector based on the perceptually organized sub-codebooks. The second method identifies a vector, from one of the perceptually organized sub-codebooks, to perceptually model the speech signal input.

Abstract: 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.

Abstract: A transmitter system (18) which transmits a communication signal (14) through a phased-array antenna (10) uses a signal processor (26) and a multiplicity of direct modulators (30). Each direct modulator (30) drives a single element (12) of the antenna (10). Each direct modulator (30) receives a digital baseband phase point data signal (62) from a digital data stream (28). The digital data stream (28) also conveys digital beam formation data (60). Each direct modulator (30) digitally combines the baseband phase point data (62) with the beam formation data (60) to produce digital streams that modulate an RF carrier signal (34). The digital data stream (28) is generated by a phased-array signal processor (26) which processes user data bits (86) received from any number of input signals (22) and processes beam signals (24). In one embodiment, the signal processor (26) calculates phase point data (62) representative of all input signals (22).

Abstract: A method and apparatus for communicating between wireless communication devices (120, 131, 140) uses a high-altitude communication platform (110) to provide an interface between the devices. The platform (110) enables multiple signals from multiple sources to be combined into one signal which is sent to a ground device (120). The ground device (120) can send a combined signal to the platform (110) which the platform (110) can then separate and send to multiple destinations. The platform (110) can be used as a bridge between satellites (1310, 1312) which are incapable of direct communication, thus enabling a fully connected network to exist without full coverage from satellites.

Abstract: The invention describes a method and system for channelization through the application of a weighted chirp pulse. The impulse response of a desired filter weighting is applied to the output of a chirp pulse generator (FIG. 1, 150). The resulting weighted chirp pulse is then applied to the a first columnar Bragg cell (80) while an unweighted chirp pulse is applied to a second columnar Bragg cell (90). A modulated energy beam (55) is then allowed to pass through both Bragg cells. The resultant spatially dispersed energy beam (95) is then applied to lens (120) and projected onto a detector array (130). The detector array (130) then extracts the subscriber transmitted information from the projected interference pattern.

Abstract: The attitude of a physical platform (62) is altered by a summation of forces from an attitude actuator (74), disturbance forces (80) and random noise (82). Attitude sensors (64) sense the attitude of the physical platform (62) and output measured attitude parameters to a disturbance force effects (DFE) filter (66) and an attitude filter (68). The DFE filter (66) outputs an attitude perturbation command to the attitude filter (68) and a command translator (72). Effects of the attitude perturbation are used by the DFE filter (66) to estimate the effects of disturbances on the physical platform (62). A trigger signal (76) from the attitude actuator (74) is used by DFE filter (66) to select an appropriate gain matrix used in the estimation process.

Abstract: At least one ground station (120) and at least one subscriber unit (SU) (130) allow users to perform user-aided registration procedures in satellite communications system (100). Ground station (120) and SU (130) communicate with each other using at least one communications satellite (110). The user-aided registration procedures (400, 500, and 600) enable border crossings to more accurately be processed by the system (100). Registration region information is presented to a user using a display device. A user response is processed by the SU and the ground station during registration procedures.

Abstract: A spacecraft (10) body (20) located in an external magnetic field (12) has a substantially unbalanced electrical power bus (18) that generates a composite local magnetic field The electrical power bus (18) substantially surrounds an external surface (22) of the spacecraft (10). Current in the electrical power bus (18) is solar panel (14and 16) and/or battery (34) generated and can flow in different directions through different current paths. Electrical loads (58) are coupled to power converters (56) and current path switches (54) to couple the power converters (56) to the various current paths. A controller (28) takes sensor data (82), determines a required attitude adjustment torque (84), translates that adjustment torque into a composite magnetic field (86), determines an unbalanced bus current profile (88) to generate that composite magnetic field, selects a current source (90) and regulates current path switches (92) to achieve a desired attitude adjustment torque for the spacecraft (10).

Abstract: Multiple, different, independent constellations (10, 20) of satellites (2, 21-23) share a portion of a common frequency spectrum such as a single carrier frequency. The satellites' antennas (11) may be either multi-beam or omni-directional, while those of earth stations (13, 14) are directional. When interference occurs between communications of a satellite (31) of a first constellation (10) and a satellite (41) of a second constellation (20), any of several interference-mitigation options may be employed, such as the first satellite (31) handing off communications to a second satellite (32) of the same constellation (10), or temporarily suspending communications. The remedial action may occur in response to either predicted or detected interference.

Abstract: A system and method provides signaling privacy for communications between nodes of a communications network (30). Multiple logical links exist between distinct network nodes (38-40, 42, 50-53) of the communication network (30). Signaling privacy is achieved by a subscriber unit (80) providing encryption/decryption of signaling data messages at the messaging level. The subscriber unit (80) employs a signaling encryptor/decryptor (86) along the signaling path, which enables the signaling data messages to be separately encrypted from data on the traffic channel. The encrypted signaling data can then be sent along a different logical link from the traffic, while maintaining cipher key synchronization between the signaling encryptor/decryptor (86) and a network encryptor/decryptor (78) at a remote end of the logical link which transports the encrypted signaling data.

Abstract: A method and apparatus have been described for combining multiple satellite constellations into a cooperative network. A GEO tier of satellites receives information to be broadcasted to earth. The GEO tier receives the information from global hubs, regional hubs, and local hubs. Local program material is combined with regional and global program material by either the regional hub or a GEO satellite.

Abstract: A method for a radio frequency communication unit (110) (CU) to hand off from a losing node (120) to an alternate node (122) estimates one or more alternate node uplink times (240) and alternate node uplink frequencies (242), which the alternate node uplink signal comprises. During handoff, the CU (110) ceases communications with the losing node (120) and immediately begins communications with the alternate node (122) using the uplink time and uplink frequency. A CU apparatus (300) uses a processor (302) for carrying out calculations necessary for estimating the alternate node uplink time and frequency. Information necessary for the calculations, such as a downlink signal time-of-arrival and Doppler offset, are collected by a CU receiver (306). The CU receiver (306) and a CU transmitter (304) are used to support downlink signals (142) and uplink signals (140), respectively, between the CU (110) and a node (120, 122).

Abstract: A method for assigning a system location to an ISU (32) residing in a wireless communication system coverage area (20) that has a plurality of billing territories (40). Base points (42) are defined to be proximate the billing territories (40) such that each of the base points (42) provides a system location for a corresponding billing territory (40). Each of the billing territories (40) has a plurality of reference points (44) distributed therein in accordance with a geographic independent algorithm such that each of the reference points (44) is described by an offset from the corresponding base point (42) of the corresponding billing territory (40). By obtaining an actual location (54) of the ISU (32) and identifying one of the reference points (44) closest to the actual location (54), the ISU (32) is assigned the system location of the identified reference point (44). In a preferred embodiment, the method and apparatus of the present invention are used in a mobile satellite system (19).

Abstract: A global message delivery system (100) transmits messages to messaging devices (130) using a plurality of satellites (110). In order to facilitate message delivery, the surface of the earth is divided into a number of logical delivery areas (202) (LDAs). Each satellite provides at least one beam (210) which spans one or more LDAs (202). When a request is received (704) to deliver a message to a messaging device (130), an Opportunity Table (600) is used to quickly determine which beam (210) to use to deliver the message. The Opportunity Table (600) correlates the messaging device's location and upcoming activation times with which beams (210) are covering which LDAs (202).

Abstract: 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.

Abstract: Originating and terminating units (32, 36) communicate through a network (22) containing satellites (46, 50, 52) and gateways (44, 48). The network (22) receives user-prioritized lists (62) of protocols from the respective units (32, 36). The network (22) compares the lists (62) to determine the highest-priority common protocol. If a common protocol exists, the network (22) establishes a link between the units (32, 36) utilizing the common protocol and excluding the gateways (44, 48). If a common protocol does not exist, the network (22) selects as originating and terminating protocols the highest-priority protocols in the respective lists (62). If the originating protocol consumes a greater number of resources, the network (22) establishes the link, translating between protocols in an originating gateway (44) and excluding a terminating gateway (48). Otherwise, the network (22) establishes the link, translating in the terminating gateway (48) and excluding the originating gateway (44).

Abstract: 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.

Abstract: One or more deployable thermal panels (24, 28, 70) are actively controlled throughout the orbit of a satellite (20) to provide thermal dissipation. Adjusting the incident angle between the panel (24, 28, 70) and the sun and controlling the flow of fluid through optional flexible heat pipes loads and unloads heat to provide thermal stability for components (62) which have special thermal requirements. An optional antenna panel (70) on a nadir side (64) of the satellite (20) offers an antenna side (74) on one surface and a thermal radiating side (72) on an opposing surface. In addition, thermal panel movements are controlled (96) to provide counter-disturbance torques (140).