Abstract: A method and apparatus for redistributing power radiated by an antenna comprised of a plurality of antenna elements. An antenna directivity estimator function is performed to screen out inappropriate antenna directivity profiles from a plurality of antenna directivity profiles, thereby determining one or more remaining, appropriate antenna directivity profiles. An optimizer function is performed on the remaining, appropriate antenna element directivities to determine a phase distribution for the antenna elements based on a desired power distribution for the antenna.

Abstract: A dual-band multiple beam antenna system for a communications satellite sharing a set of reflector antennas for the transmit and receive frequencies. One set of reflectors is common to both the downlink and uplink frequencies. The feed horns are diplexed and exhibit frequency-dependent radiation patterns that separate the phase centers over the downlink and uplink frequency bands to obtain dual-band performance. The focal point of the reflector is in close proximity to the phase center corresponding to the downlink frequency band. The phase center for the uplink frequency band is spaced a predetermined distance from the phase center of the downlink frequency band. According to the present invention, the uplink frequencies are defocused and the downlink frequencies are focused thereby creating identical radiation patterns at both frequency bands and over the coverage region of the communications satellite.

Abstract: An apparatus and method are shown for receiving multi-path signals. A rake receiver is used to receive multi-path signals. The rake receiver contains multiple fingers that act as correlators, where each finger is synchronized to one of the multi-path signals. Each finger of the rake receiver includes a variable delay element. The delay of the variable delay element in each finger may be determined by calculating the amount of time for a signal to travel from an antenna to the receiver, due to the path traveled, and setting the delay based on the measured travel time. The delay of the variable delay element in each finger may also be determined by scanning through a range of delays of the variable delay element and measuring an output signal level of the finger, the variable delay element then being set to the delay corresponding to the highest measured output signal level.

Abstract: A power system for a satellite includes a high power amplifier that has a control input. The high power amplifier has a minimum effective isotropic radiated power. A controller is coupled to the control input. The controller generates a control signal to adjust a saturated power output of the high power amplifier to the minimum effective isotropic radiated power.

Abstract: Apparatus, and an associated method, for facilitating selection of optimal antenna weightings by which to weight signals sent in a communication system that utilizes closed-loop transmit diversity. A deterministic perturbation gradient approximation technique is utilized in which perturbation vectors are selected by a selector and applied, by an applicator, to antenna weighting elements. A selected set of perturbation vectors are applied to the antenna weighting elements in both a positive direction and a negative direction. A detector at a receiving station measures in disassociated with the signals communicated thereto, once weighted with the perturbation vectors. A single-bit feedback value is returned to the sending station, and the antenna weightings are appropriately adjusted.

Abstract: Frequency converting circuits each correspond to one satellite and convert frequency bands of two types of polarization signals received from the corresponding satellite into two intermediate frequency bands that do not overlap with each other. Signal couplers each correspond to one satellite and perform frequency-multiplexing of the two types of polarization signals from the corresponding satellite having their frequency bands converted, to generate a first combined signal. A signal rearranging circuit selects any two first combined signals from the two first combined signals allowing duplicate selection, and takes out any one polarization signal from each of the selected first combined signals, and performs frequency-multiplexing of the taken out two polarization signals to generate a second combined signal.

Abstract: A repeating apparatus and method using wireless optical transmission is disclosed. The repeating apparatus includes a donor device for transmitting two identical copies of an optical signal by receiving a RF signal from a base station and electro-optic converting the RF signal to an optical signal, and for transmitting a RF signal by receiving two identical copies of the optical signal and optic-electro converting the optical signal to a RF signal; and a coverage device for transmitting a RF signal to a mobile communication terminal by receiving two identical copies of the optical signal from the donor device and optic-electro converting the two identical copies of the optical signal to the RF signal, and transmitting two optical signals to the donor device by receiving the RF signal from the mobile communication terminal and elector-optic converting the RF signal to the optical signal.

Abstract: A transmission weight vector computing unit computes transmission weight vectors. A transmission weight vector correcting unit obtains a corrected transmission weight vector W?(t). A predicted receiving power computing unit computes a predicted receiving power value Y(t). If a difference between the predicted receiving power value Y(t) and a predicted receiving power value in the past Y(t-T) is less than a threshold value, an update unit selects the corrected transmission weight vector W?(t). If, on the other hand, the difference is greater or equal to the threshold value, the update unit selects a corrected weight vector in the past W?(t-xT). If the modulation method is QPSK, a setting unit selects the transmission weight vector W(t). If the modulation method is 16 QAM, the setting unit selects the corrected transmission weight vector W?(t) or W?(t-xT) and outputs it as a final transmission weight vector signal.

Abstract: Briefly, a method and apparatus for decoding and authenticating an antenna is disclosed. The method may include detecting attachment of an antenna to a transmitter by authenticating a cipher received from the antenna. The method further includes suspending transmission if the antenna is not attached to the transmitter.

Abstract: A satellite is used to route push-to-send messages among terrestrial base stations. Reduced push-to-send delays thereby may be provided, when a source push-to-send radioterminal is widely separated from a destination push-to-send radioterminal. Satellite routing only may be used when the source push-to-send radioterminal and the destination push-to-send radioterminal are not communicating with a single terrestrial base station or with a group of terrestrial base stations that are proximate one another. A destination base station that is communicating with the destination push-to-send radioterminal may be determined at the satellite, at a satellite gateway and/or at a central server.

Abstract: A communications system comprises at least one beacon device capable of wireless message transmission and at least one portable device capable of receiving such a message transmission. The beacon is arranged to broadcast a series of inquiry messages each in the form of a plurality of predetermined data fields (INQ) arranged according to a first communications protocol, such as Bluetooth. For the delivery of additional data via broadcast, the beacon adds to each inquiry message prior to transmission an additional data field (BCD) carrying audio data, with the portable device receiving the transmitted inquiry messages, reading the audio data from the additional data field, and reproducing the audio to a user.

Abstract: A communications system includes an antenna that produces a series of beams which divide a service region into a plurality of contiguous cells, and dynamically modifies cell boundaries so that the system's allocated communication spectrum is efficiently utilized.

Abstract: A wireless communication system includes multiple wireless communication platforms carrying reflectors for providing spot beams. By using multiple platforms, the payload can be split. Each platform carries only a part of the reflectors needed to provide coverage for a certain geographic area. That allows the reflectors to be of larger size providing smaller spot beams. The multiple platforms of the wireless communication system are designed to be interchangeable. Therefore, only one standby platform is necessary for backup. By further providing an closed-loop pointing control method it is possible to keep multiple platforms pointed accurately relative to each other and relative to the user coverage area.

Abstract: An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear “ratcheting” in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.

Abstract: In a radio communication system comprising a plurality of stations (100a,100b,100c) operating in a peer-to-peer mode, each station stores information relating to the transmission parameters of other stations. Such information may include the frequency offset and received signal strength of signals from the other stations. One station acts as central controller and allocates time slots for transmission from a first station (100a) to a second station (100b). Before the first station (100a) receives a signal from the second station (100b) it makes initial adjustments to its receiver circuitry depending on the stored information about previous signals received from that station (100b). This simplifies the task of adjusting the receiver circuitry during the preamble of the signal transmitted by the second station (100b).

Abstract: A method and system for optimizing the use of antennae in a CDMA distributed antenna system. A pathway manager may identify and select an optimal antenna to transmit a wireless signal from a BTS to a receiver. The non-selected antennae may be disabled from transmitting signals to the receiver by suppressing the Walsh code and PN offsets of the BTS and receiver. The pathway manager may use criteria such as availability, proximity, reliability, and strength of signals and antennae to select an optimal antenna. Communications between the receiver and the antennae may be used to determine such criteria. By selecting an optimal antenna, the pathway manager may conserve energy from a BTS and reduce power requirements for an antenna system.

Abstract: A communication satellite cellular coverage pointing correction using uplink beacon signal is provided. A ground-based beacon transmits a monopulse tracking signal or a Traveling Wave Coupler (TWC) tracking signal to a specialized tracking feed section located within each uplink and downlink antennae of a satellite. From the monopulse or TWC tracking signal, a pointing correction is determined for each reflector, for example, the angle off boresight and the angle between the present beam direction and the target direction. Each reflector is then gimbaled to re-point the reflector to the target area. In this way, both uplink and downlink antennae are provided with closed-loop control over antenna pointing.

Abstract: An antenna unit has a coaxial cable firmly connected and fixed to an antenna substrate by an easy soldering process and provides freedom in pattern formation and mounting of parts on the antenna substrate. The antenna unit includes an antenna substrate on which an antenna element and antenna circuit parts are mounted, and on which a power supply pattern or a ground pattern is formed. A shield case is attached to the antenna substrate so as to cover the mounted parts. A nearly C-shaped notch is formed on the main surface of the shield case opposed to the antenna substrate to form a tongue piece-shaped hold-solder part. A coaxial cable is connected to a connection part formed on the antenna substrate and led from a lead part formed on a side surface of the shield case.

Abstract: A radio frequency transmitting and receiving module having a support housing that has a hexagonal face member mounted to the support housing. This face member has an antenna for transmitting and receiving radio frequency signals. Mounted within the support housing is circuitry for (a) conducting radio frequency signals to the antenna for transmission by the antenna, and (b) conducting radio frequency signals received by the antenna from the antenna for processing. Such a module, functioning as a hexagonal power unit core, can be fixed in a honeycomb cellular array employing “plug and play” assembly techniques.

Abstract: An apparatus and method for a time division multiple access (TDMA) network backbone comprising a plurality of nodes interconnected by links. Each node has receive antennas and transmit antennas for communicating radio frequency (RF) bursts, and a node control for communicating node information. The receive antennas are operated in accordance with TDMA receiving slots and the transmit antennas are operated in accordance with TDMA transmit slots. A timing reference subsystem provides timing signals for the nodes for efficiently utilizing the transmission links formed between given nodes.

Abstract: A system and method for efficiently and effectively simulating hardware-in-the-loop testing of a wireless communications network. The system and method employs an optical matrix-vector multiplier (MVM) for performing optical signal processing to simulate radio frequency (RF) signal propagation characteristics in a mobile wireless communications network. Specifically, the system and method employs an optical modulator, which is adapted to modulate optical energy with signal energy, such as radio frequency (RF) signal energy, propagating from a first group of transceivers of the network to form a vector of optical signals. The optical matrix-vector multiplier (MVM) receives the vector of optical signals, and has a matrix of optical channel weights which are modifiable in accordance with desired parameters to represent at least on parameter of the wireless network. The optical MVM is further adapted to output signals based on the received vector of optical signals and the optical channel weights.

Abstract: A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range.

Abstract: A wireless communication system includes platforms that generate spot beams and wide-area beams. The system includes a network operations controller that receives signals from user terminals. User terminals determine the signal strengths of the spot beams and the wide-area beams and a ratio may therefore be calculated between the spot beam and the wide-area beams. Based upon the ratio of the spot beam strength and the wide-area beam strength, the network operations controller may adjust the orientation of the platforms relative to the earth to correct for pointing errors and, the network operation controller may compensate as is best possible depending on the type of antenna, a correction for distortion in the antenna.

Abstract: A low profile, vehicle mounted, in-motion tracking, satellite antenna includes a pair of antenna assemblies mounted in parallel on a rotatable platform. Each antenna assembly includes two subreflectors with a plastic matching element. The outputs of the two antenna assemblies are coupled with a single phase shifter. The combined outputs are retransmitted to a receiver inside the vehicle. The satellite antenna also includes a receiver for receiving channel selection data and/or for providing two-way communication with equipment inside the vehicle. The antennae, transmitter and receiver are self-powered by a storage device which is charged by a wind driven generator. A retractable radome lowers to a lower profile when the antenna is not in use.

Abstract: A method and implementation of wireless communication are disclosed in which wireless signals are exchanged between at least one remote client and a directional antenna array associated with a wireless network, wherein the directional antenna array includes a plurality of antenna elements. A statistical matrix analysis is performed for each of the at least one client and the antenna array, in order to locate angles associated with directions of each client with respect to the antenna array. Values are determined for weighting factors for RF signals of each of the respective plurality of antenna elements, so as to create predetermined phase differences between the signals of the plurality of antenna elements. The predetermined phase differences are used to direct at least one null toward at least one source of interference, so as to avoid signal interference.

Abstract: A dual-band multiple beam antenna system for a communications satellite sharing a set of reflector antennas for the transmit and receive frequencies. One set of reflectors is common to both the downlink and uplink frequencies. The feed horns are diplexed and exhibit frequency-dependent radiation patterns that separate the phase centers over the downlink and uplink frequency bands to obtain dual-band performance. The focal point of the reflector is in close proximity to the phase center corresponding to the downlink frequency band. The phase center for the uplink frequency band is spaced a predetermined distance from the phase center of the downlink frequency band. According to the present invention, the uplink frequencies are defocused and the downlink frequencies are focused thereby creating identical radiation patterns at both frequency bands and over the coverage region of the communications satellite.

Abstract: A Wireless Communication Device (WCD) includes multiple fingers that track one or more tracked transponder beams. Each tracked beam is from a respective tracked transponder. The WCD determines a tracked-beam searcher energy for each of the tracked beams, and an untracked-beam searcher energy for each of one or more untracked beams from each of the tracked transponders. The WCD attempts to determine a preferred one of the untracked beams that should become a tracked beam. This determination is made based on the tracked-beam and the untracked-beam searcher energies. The WCD assigns, or alternatively, reassigns, a finger to the preferred untracked beam when the attempt to determine a preferred untracked beam is successful. The transponders may be satellites or base stations.

Abstract: A method provides for trunk group satellite switching using a code division multiple access (CDMA) scheme. The method includes receiving inbound satellite beams carrying individually encoded user signals including a plurality of inbound trunk groups, processing and mapping the trunk group elements to a plurality of outbound trunk groups, routing the outbound trunk groups to appropriate outbound satellite beams and transmitting the outbound beams based on common destination parameters. The trunk group switching allows for a reduction of on-board switching complexity, volume, and costs.

Abstract: A system and method for maximizing throughput in a telecommunications system is disclosed. The system includes an antenna system using fixed narrow beams that transmits and allows improved capacity gain to be realized without degrading call performance. The system can include: forming a plurality of directional narrow uplink beams at a main antenna; receiving communications signals on the plurality of directional uplink beams; periodically scanning across the plurality of uplink beams associated with a given call; assessing a set of beams from the plurality of uplink beams based upon a quality of reverse link information; selecting a first subset from the set of beams to be turned off when the quality of reverse link information reaches a first predetermined value; and instructing the subset to not transmit a traffic channel and to continue to transmit the power control sub channel.

Abstract: A modular cellular wireless communication base station includes a plurality of active radiator modules located at a desired antenna location. Each module includes at least one antenna, a transmitter, and a receiver. A beam forming network controls relative amplitudes and phases of each of the modules. An RF front end transmits over a low power link with the active radiator modules via the beam forming network and receives over the low power link via a low noise amplifier. A delay diversity module provides a transmission CDMA delay diversity.

Abstract: This invention is a wireless communication medium processing apparatus which carries out communication with a wireless communication medium, to carry out at least one of reading and writing as to information which was stored in the wireless communication medium, and has a plurality of antenna, a transmission divider which was connected to the plurality of antennas, and a reception compositor which was connected to the plurality of antennas, and is characterized in that the transmission divider divides an inputted signal to output the plurality of antennas, and the reception compositor combines signals from the plurality of antennas and outputs it.

Abstract: A multiple purpose antenna system for installation on a highway truck to receive and transmit signals. The system includes an antenna for communication of electromagnetic frequency signals having multiple band widths, a multiplex unit coupled to the antenna having circuitry for simultaneously passing multiple signals of band widths, and a filter unit. The filter is coupled to the multiplex unit for filtering signals received from the multiplex unit into multiple sets of band width ranges. The sets include a first frequency range for use by a first receiver apparatus, a second frequency range for use by a second receiver apparatus, and a third frequency range for use by a third receiver apparatus. The filter unit may be included within a satellite electronic communications unit. The first receiver apparatus may be a weather band radio apparatus. The third receiver apparatus may be an AM/FM commercial radio.

Abstract: A portable wireless communication terminal device has a data communications function and a telephone function and includes a casing, a display having a display section exposed through an opening of the casing, a circuit board installed in the casing and having the display on one surface of the circuit board, a first antenna electrically connected to the circuit board and disposed on an opposite side to the display inside the casing, and a second antenna electrically connected to the circuit board and mounted on a periphery of the display inside the casing. The device maintains a stable antenna characteristic and communication quality even if it is placed on a table or if the fingers of a user cover the backside of the device.

Abstract: A system for transmitting data to a plurality of satellites is provided. A first satellite in an orbital slot has an associated receive antenna, and is configured to receive signals in a first range of frequencies. A second satellite in the orbital slot has an associated receive antenna. The second satellite is separated from the first satellite by at least a first separation angle, and is configured to receive signals in the first range of frequencies. A first earth uplink antenna, located at a first earth location, is capable of transmitting a first uplink beam at the receive antenna of the first satellite. A second earth uplink antenna, collocated at the first earth location, is capable of transmitting a second uplink beam at the receive antenna of the second satellite. The first uplink beam includes first signals at the first range of frequencies, and the second uplink beam includes second signals at the first range of frequencies.

Abstract: An antenna system is disclosed. The antenna system includes at least one first and second antenna. The at least one first antenna is located about a first portion of a mobile structure and is capable of receiving satellite and terrestrial re-transmitted satellite signals. The at least one second antenna is located about a second portion of a mobile structure and is capable of receiving satellite and terrestrial re-transmitted satellite signals. Either the at least one first or second antenna receives the satellite and terrestrial re-transmitted satellite signals and the other of the at least one first or second antenna becomes operative when the satellite and terrestrial re-transmitted satellite signals being received by the at least one first or second antenna is obstructed. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.

Abstract: A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range.

Abstract: Mechanisms for selecting a set of antennas for use in a wireless communication system are disclosed. The selected set of antennas is for use in communicating data in a wireless local area network (WLAN) comprising an access point and a plurality of mobile stations. The access point includes a baseband chip capable of adapting various radio frequency (RF) units. Each RF unit in turns includes a plurality of RF sub units, each of which connects to a plurality of antennas. The access point thus includes a number of antennas that, together with the RF units and the baseband chip, form a smart antenna. To identify the selected set of antennas to communicate with a particular mobile station, the access point initially uses a first set of antennas each in a RF sub unit. From this first set of antennas, the access point identifies a first set of winner antennas and a first set of non-winner antennas.

Abstract: A satellite system is provided that includes a receive antenna system to receive one of C-band and/or Ku-band signals and a transmit antenna system to transmit one of C-band and/or Ku-band signals. A payload section may be coupled between the receive antenna system and the transmit antenna system. The satellite system may provide broadband communications at C-band and/or Ku-band.

Abstract: A system and method for positioning a dish antenna having a plurality of low noise block converters for the simultaneous reception of signals from a plurality of satellites in a direct broadcast satellite system. An integrated receiver/decoder alternately powers at least two low noise block converters to sample signals for comparison to a threshold value to detect a peak signal for each of the low noise block converters. When the peak signals are detected, they are compared to a master threshold to indicate a master lock for the system.

Abstract: There is provided an antenna array apparatus using a GPS signal in a base station and a beamforming method thereof. In the antenna array apparatus, a GPS signal processor receives GPS position information from a mobile station and calculates the position information of the mobile station. A signal processor calculates a weight vector using the position information to form a transmission/reception beam. A transmission/reception beamformer forms the transmission/reception beam according to the weight vector.

Abstract: A space-based network for a satellite radiotelephone system includes at least one receive-only satellite and at least one transmit satellite. The transmit satellite can be a transmit-only satellite or a transmit and receive satellite. The receive-only satellite(s) are configured to receive wireless communications from a radiotelephone at a location over a satellite frequency band. The transmit satellite(s) are configured to transmit wireless communications to the radiotelephone at the location over the satellite frequency band. By providing at least one receive-only satellite and at least one transmit satellite, space-based networks can offer a significant link margin, without the need to undesirably burden the radiotelephones themselves to achieve this link margin.

Abstract: A repeater is disclosed which is usable to permit a satellite phone, normally requiring a direct line of sight link to an orbiting satellite, to communicate with the satellite when the satellite phone is otherwise obstructed from communicating with the satellite. The repeater is usable in any situation in which the satellite phone is blocked from a direct line of site to the satellite, such as inside a building, aircraft, or natural formation (e.g., cave).

Abstract: A method detects relaying of a contactless data communication by a radio amplifier for intercepting and manipulating the communication to achieve an unauthorized authentication. The method involves transmitting an electromagnetic field successively from at least two spatially separated antennas of a transmitting unit, receiving the transmitted fields in a receiving unit, determining field strength vectors of the received fields allocated to each antenna, and comparing actual values of the vectors with prescribed nominal values stored in a nominal value field that maps the true field strength distribution in multi-dimensional space around the transmitting unit. The actual field strength magnitude and the reception angle between the transmitting antennas can be determined from the vectors and compared with stored nominal values in this manner. When the determined actual values match prescribed nominal values of the nominal value field, the occurrence of a relaying of the signal can be reliably excluded.

Abstract: First and second waveguides which have respective axes thereof arranged parallel to each other are respectively held by dielectric feeders. A projection wall or a thick wall is formed as a correction part on a front surface of a waterproof cover which covers radiation parts of the dielectric feeders. Due to such a constitution, when radio waves transmitted from neighboring first and second satellites are converged by a reflector and are incident on the inside of respective waveguides, it is possible to delay a phase of radio waves which pass the waterproof cover by the correction part (projection wall or thick wall) so that it is possible to adjust such that radiation patterns of radio waves which are incident on the respective waveguides are reflected on a common portion of the reflector whereby the required reflector can be miniaturized.

Abstract: Likelihood determining section 111 calculates likelihood of hard decision data of a receive signal using pre-hard decision data of the received signal, and compares the calculated likelihood with a predetermined threshold 1. Switch control section 112 controls switch section 113 so that the section 113 outputs an error signal to weight control section 105 when reliability of the hard decision signal is high, corresponding to a determination signal from likelihood determining section 111. Weight control section 105 calculates a weight based on the error signal from switch section 113.

Abstract: A transponder system, which may be on a spacecraft, provides communications to and among user terminals for audio-bandwidth signals. The transponder includes a receiver for uplink signals, and a digital channelizer which separates the various independent uplinked signals. The separated uplinked signals are then grouped together with other signals destined for the same downlink beam, and routed to the corresponding beam input port of a beamformer. The beamformer, in turn, energizes or feeds those antenna elements which are required to form the desired antenna beam. In order to provide a capability for handling signals having a bandwidth greater than that of the audio signals, as might be required for providing the capacity to handle Internet signals, for example, a wideband augmentation equipment (WAE) is coupled in such a manner as to bypass the digital channelizer, to thereby provide a wideband path through the system, bypassing the narrowband channelizer.

Abstract: This disclosure provides a communications system using a span-loaded flying wing, traveling at relatively slow speeds, that can remain airborne for long periods of time. The communications system uses the airplane as a long term high altitude platform that can serve at lest one of a number of potential functions. One function is to link to a ground station using radio wave signals and a satellite using optical signals. Another function is to serve as a relay station between ground communication nodes and individual end-users. Because the aircraft can tightly hold a station, the end-user's antennas do not need to be continuously adjustable. For such a system, a large number of aircraft can be used, with the end-user antennas being configured for a narrow beamwidth so as to allow frequency reuse for different communication links.

Abstract: A method and apparatus for ensuring a correct satellite signal connection. Specifically, a user selects a satellite signal via an integrated receiver/decoder (IRD) from at least one satellite, and the IRD sends a command signal to a selector switch to acquire and lock onto said satellite signal. The IRD repeats transmission of the command signal to the selector switch once the IRD has acquired and locked onto said information signal. Thus, in the event that the selector switch failed to switch to a low noise block converter (LNB) corresponding to the initial command signal, then the repeated command signal helps to ensure that the selector switch switches to the LNB corresponding with the latest command signal sent by the IRD.

Abstract: Information content is nonidentically mapped between service link carriers and feeder link carriers at a cellular satellite. A reduced number of satellite feeder link carriers compared to the number of satellite service link carriers and/or a reduced total bandwidth of the satellite feeder link carriers compared to the satellite service link carriers thereby may be obtained.

Abstract: An active antenna power interface circuit couples a supply voltage from a radio receiver to an antenna feed. The circuit comprises a DC power input and a power switching element connected in series between the DC power input and the antenna feed. The power switching element has a control input for selecting a conducting state or a nonconducting state of the power switching element. A high side voltage sensor senses a first voltage proportional to a voltage at the DC power input. A low side voltage sensor senses a second voltage proportional to a voltage at the antenna feed. A controller is coupled to the control input and to the voltage sensors. The controller places the power switching element into the conducting state, samples the first and second voltages, calculates a voltage difference in response to the first and second voltages, compares the voltage difference to an upper limit and a lower limit.