Abstract: 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 (20) transmits a data signal (40) and a pilot signal (50). The data signal (40) and the pilot signal (50) are substantially orthogonally polarized. A user terminal (30) receives the orthogonally polarized data signal (40) and pilot signal (50). The user terminal includes a channel information recovery circuit (250) and a channel effects mitigation circuit (240). The channel information recovery circuit (250) characterizes the communications channel by analyzing the pilot signal (50), and then provides the channel information (260) to the channel effects mitigation circuit (240) which then mitigates the effects of the channel.

Abstract: Methods (600, 700), an access controller (350), and a communication system (300) for optimizing utilization of a wireless communication link in a limited bandwidth communication system or network are provided. Statistical multiplexing is achieved by partitioning a wireless communication link (240) into multiple communication channels (250) and assigning communication sources (220) to communicate information over an air interface for a predetermined time interval, where the number of communication sources (220) assigned to the communication channels (250) during a particular time interval exceeds the number of available communication channels (250). The methods (600, 700), access controller (350), and communication system (300) disclosed also allow a system operator to provide varying levels of quality of service (QoS) guarantees in a communication system or network using statistical multiplexing by designating varying levels of QoS among the communication channels (250).

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: A method and apparatus for combining and separating groups of signals starts by a transmitter (500) receiving a number of CDMA-encoded signals from data sources (510). The CDMA-encoded signals are sorted (502) based on their intended destinations. Those CDMA-encoded signals which are intended for a common destination are multiplexed (504) together into a group. The group is further CDMA encoded (506) using a group code and the encoded group is transmitted (508) to an intermediate transceiver (600) or a destination transceiver (700). The intermediate or destination transceiver decodes (604, 704) the group using the appropriate group code and routes the resulting group of signals accordingly.

Abstract: A method and apparatus predicts a ground-to-satellite terminal's (16) percentage of successful communication linkage time to at least one satellite of a communication system in response to a terminal blockage profile (410), as created from the location of an antenna of the terminal, and a satellite blockage profile (412). The prediction may also be based upon a weather model data base (358) corresponding to the area where the terminal is located.

Abstract: A method and apparatus for communicating with a high-altitude communication platform (110) which combines multiple signals from multiple sources 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 ground device (120) also can provide spectral reuse by orienting directional antennas (360-362) toward the communication platform (110) and one or more spatially diverse other wireless devices.

Abstract: A method and apparatus for responding to a blockage environment (50) in a communication system includes creating (158, 163) a terminal blockage profile and/or a satellite blockage profile with respect to terminal antenna (19) and responding (200) to the terminal blockage profile and/or the satellite blockage profile to prevent fading and/or blocking of communication pathways (15, 18) between one or more satellites (12) and the terminal (16).

Abstract: In a satellite (20), two-axis solar panel drives (56, 58) allow two degrees of rotational freedom of movement for solar panels (22, 24). Regulation of electrical current loops (46, 48) within the solar panels (22, 24) generates a magnetic field. When the solar panels (22, 24) are tilted about an overturning axis (28), the magnetic field provides a component of a control torque about a pitch axis (30). An on-board processor (52) commands the panel drives (56, 58) and a magnetic torque actuator (60) to instantaneously and simultaneously damp disturbance torques about a windmill axis (26), an overturning axis (28), and a pitch axis (30). The processor (52) allows disturbance torque to be corrected continuously rather than periodically over the course of an orbit. Counter-disturbance torques (90) are applied (88) in synchronism with a satellite nutation frequency (76) but out of phase with the nutation so that nutation is damped.

Abstract: 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.

Abstract: A satellite attitude/orbit control system (300) for managing a satellite cluster (200) in a satellite constellation (207). A satellite cluster (200) comprises a master satellite (203) and secondary satellites (201, 202, 204, 204). The master satellite (203) receives sensor data from secondary satellites (201, 202, 204, 204) and combines such secondary sensor data with master sensor data from a master satellite (203) to calculate attitude/orbit estimates for all satellites within the satellite cluster (200). Attitude estimates are forwarded to each satellite for initiation of attitude/orbit control. Each satellite cluster (200) subordinates to a constellation master satellite (301) for receiving additional attitude/orbit estimates for use in determining and controlling satellite attitude/orbits.

Abstract: An enhanced services communication system (10) has a standard services region and an enhanced services region (58) in which communication may be carried out. Subscriber units (49, 109) located within the enhanced services region (58) request enhanced services that include dynamic allocation of bandwidth. A variable bandwidth repeater switch (42) evaluates the availability of requested bandwidth and allocates the bandwidth to the subscriber units (49, 109) when available. Transmission of data using enhanced services occurs using wideband wired interfaces (115), wideband wireless interfaces (70), or PSTN interfaces (103). Selection of dynamic allocation of bandwidth may rely upon economic, propagation duration, or link quality factors, among other considerations.