Abstract: There is disclosed an antenna system and method of operation which allows for a large number of antennas to transmit signal streams to a similarly large number of receiver/transmit ports over a single communication channel. In operation, there is created a plurality of frequency bands each identified with a particular one of the antennas. The signal streams from each antenna are mixed so that they fall within the frequency band assigned to that antenna. The reduced signal streams, which now all fall within a preselected frequency band for each antenna, are then combined into a single wide band signal stream and communicated over a single communication channel to the remote end where the signals are separated into their respective signal streams and the separated signal streams are then mixed to recreate the originally received frequencies. The system can be arranged such that a selection process allows multiple radios to connect to any channel of any antenna.

Abstract: A system for monitoring and adapting radio signals at a cellsite to enable improved call management for mobiles active therein. Matrix switches, advantageously separate ones for the receive side and the transmit side of the cellsite's radios, have extra ports to which other devices are connected. These devices include signal modifiers such as amplifiers, filters, attenuators or interference cancelers, through which the radio signals may be routed within the switches to enable modification of the signals on a per-channel basis. These devices further include signal generators which may inject signals such as tones or noise to ports in the switches to create pretextual radio conditions that may trigger desired call management results. An air interface controller, advantageously in combination with a cell neighborhood host controller, governs operation of the system.

Abstract: A receiving system 100 is disclosed which includes at least one antenna 101 providing a plurality of antenna beams. A first processing branch 103 is included for processing a first plurality of signals appearing within a first plurality of the antenna beams. The first processing branch 103 includes a plurality of delay paths 105 each receiving a one of the first plurality of signals from a corresponding one of the first plurality of antenna beams and applying a predetermined amount of delay thereto, the preselected amount of delay proportionate to the corresponding one of the beams. First processing branch 103 further includes a combiner 106 for combining the first plurality of signals after output from the plurality of delay paths 105. A second processing branch 104 is provided for processing a second plurality of signals appearing within a second plurality of the antenna beams.

Abstract: A system and method for continuously managing antenna beam assignment for a particular channel in a cell is disclosed. Reception conditions on the antenna beams are continuously monitored whereby wireless communications are initially assigned antenna beams based on reference, in part, to the currently prevailing reception conditions. Antenna beam assignment for continuing wireless communication is periodically updated based reference, in part, to subsequently prevailing reception conditions.

Abstract: A transmitting system (80) is disclosed which includes several antennas (801-803) providing a plurality of antenna beams. The transmit signal from transmitter 81 is sent to the plurality of antennas via routing circuitry (82). The transmit signal is divided into two or more identical signals, each delayed by a selected amount. The particular antenna to which the undelayed signal, the first delayed signal and each other delayed signal is sent is selected for any instant depending on control signals provided by control (83). Control (83), in turn, could operate from a number of factors, one being the relative strengths of the received signals at each of the antennas for that particular channel. The amount of delay could, if desired, also be controlled by control (83).

Abstract: A receiving system 100 is disclosed which includes at least one antenna 101 providing a plurality of antenna beams. A first processing branch 103 is included for processing a first plurality of signals appearing within a first plurality of the antenna beams. The first processing branch 103 includes a plurality of delay paths 105 each receiving a one of the first plurality of signals from a corresponding one of the first plurality of antenna beams and applying a predetermined amount of delay thereto, the preselected amount of delay proportionate to the corresponding one of the beams. First processing branch 103 further includes a combiner 106 for combining the first plurality of signals after output from the plurality of delay paths 105. A second processing branch 104 is provided for processing a second plurality of signals appearing within a second plurality of the antenna beams.

Abstract: A system for communicating a wide band signal across a plurlaity of narrow band channels by separating the wide band signal into two or more narrower sub-bands and modulating the developed narrower sub-bands down to baseband. The baseband channels are algebraically combined to form unique combination signals, and the combination signals are transmitted over the narrowband channels. On the receiving end, the combination signals are algebraically combined to recreate the original baseband channels. The channels are modulated up to their original frequency bands, and arithmetically combined to recreate the desired broadband signal.

Abstract: The present invention relates to a technique using interpolative coders and decoders to permit an analog input message signal to be sampled at the Nyquist rate, each sample is then encoded into a corresponding level of an X-bit code and the encoded corresponding level is then encoded into a unique corresponding digital number pair. Each digital number pair includes two separate digital signals comprising Y bits each for transmission over two separate channels or paths to a remote receiver for inverse decoding. In accordance with the present technique either half of the transmitted signal can be used to reproduce the original signal to a fair degree of accuracy and both halves can provide high-quality reproduction of the original signal.

Abstract: A digital communications satellite (12,44) receives signals from a plurality of narrow input spot-beams (14) of an uplink. It regenerates, multiplexes and routes the signals for transmission in a plurality of narrow output spot-beams (42) of a downlink. The uplink beams (14) each include a plurality of frequency re-use channels (18), while the downlink beams (42) each have only a single wide-band channel. The satellite (12,44) may multiplex the signals either before or after routing them. The spot-beams (14,42) may be fixed or scanning.

Abstract: The present invention relates to a technique for efficient spectrum utilization in mobile radio systems divided into a plurality of geometrically-shaped cells (10-21). Mobiles (24) in each cell are served by at least one base station (30-40) comprising a directional antenna having a beamwidth corresponding to the overall area of the associated cell. Each base station communicates with mobiles within the associated cell using separate primary channels (C.sub.p) within a first portion of the system frequency spectrum when a mobile is not experiencing interference above a predetermined interference level, and switches a mobile to a separate secondary channel (C.sub.p) within a selected section (f.sub.1, f.sub.2, f.sub.3) of the remaining second portion (f.sub.i) of the system frequency spectrum when the interference at a mobile exceeds the predetermined interference level. Each selected section used in adjacent portions of adjacent cells being within a different frequency subband of the second portion.

Abstract: The present invention relates to a satellite communication system comprising a plurality of limited scan spot beams which permits high transponder utilization efficiency by virtue of pooling the resources of each terrestrial footprint. In an embodiment of the invention, a satellite comprises a plurality of transponders, the signals from each transponder being directed via one or more associated scanning beams over a separate limited scanning beam region on the surface of a celestial body. In a preferred arrangement, each of the plurality of scanning spot beams is scanned linearly and parallel to the other scanning spot beams in a manner wherein each of the scanning beams covers a separate one of adjacent bands dividing the overall service region on the celestial body. By proper orientation of each of the scan regions or bands, nearly equal volumes of traffic can be served by each transponder.

Abstract: The present invention relates to a technique for increasing the rain margin of a satellite communication system which includes a satellite capable of transmitting multiple concurrent beams comprising time slot bursts in a TDMA mode. The present technique creates a small pool of TDMA time slots which are dedicated or formed at some instant of time by the rearrangement of traffic to permit the power normally transmitted in any portion of the multiple concurrent beams to be applied to one beam in a multiple fixed beam or limited scanning beam system or any portion of the beams which are directed at one ground station in a multiple unlimited scanning beam system for accessing a ground station experiencing, for example, a fade condition.

Abstract: The present invention relates to a technique for creating dedicated in-band, two-way, signaling channels between a master signaling ground station and each remote ground station of a satellite communication system using either an area coverage beam or a plurality of fixed and/or scanning spot beams. In the present technique, separate bursts of information within a superframe sequence are dedicated for only providing signaling information between the master signaling station and each ground station of the system. Each ground station, in turn, is dedicated a separate burst of information for transmitting only signaling information back to the master signaling station. Coarse ranging is performed by triangulation methods and then each ground station transmits a unique word within the predetermined time period of its dedicated signaling burst to the master signaling station.

Abstract: The present invention relates to a satellite communication system which uses a separate up-link and down-link fixed spot beam for communication with each of a plurality of, for example, spaced-apart high traffic demand ground areas and an up-link and a down-link scanning spot beam for communication with a plurality of, for example, spaced-apart low traffic demand ground areas on a time division multiple access (TDMA) basis. More particularly, a satellite repeater is disclosed for accomplishing the switching of signals concurrently received via the up-link fixed and scanning spot beams to the appropriate down-link fixed and scanning spot beams. Additionally, a transmission and a switching format is disclosed for the efficient multiple access of the low traffic demand ground station areas while still providing minimal buffering demands for the high traffic demand ground station areas.

Abstract: The present invention relates to a method of cophasing the feed elements of a transmitting or a receiving phased array antenna. To cophase a transmitting antenna, the method entails transmitting a lower sideband and an upper sideband signal from a first and a second one of the feed elements, respectively, while transmitting a carrier signal used to generate the sideband signals on all other feed elements of the array. At each receiver the reference phase angle between the received sideband signals is measured and stored. The above step is sequentially repeated for the first and a third, the first and a fourth, etc., one of the feed elements, and the phase angle measured, subtracted from the reference phase angle, and stored. With the above method, the phase angle between each feed element and the second one of the feed elements is determined and stored and subsequently transmitted back to the transmitter for use in transmitting signals to each receiver.

Abstract: The present invention relates to method and apparatus for communicating with one or more receiver stations disposed within a blackout region located in the vicinity of and surrounding each spot beam coverage area, the blackout region being caused by interference between concurrently transmitted and overlapping global coverage and spot coverage antenna radiated beams using the same frequency band despite the application of global beam interference suppression techniques at the spot beam receiving areas. Access to the receiver stations within each blackout region is provided by selectively turning off the associated interfering spot beam during a predetermined interval of time while ensuring that the power level of the radiated global coverage beam is not suppressed within the accessed blackout region to permit the global coverage beam to communicate with these receiver stations.