Abstract: Disclosed is a multiple-beam transmitting system for use in a wireless telecommunication system, including a radio transmitter assembly, which can be situated at the bottom of a base station tower, and a transmitter subassembly that can be situated atop the base station tower. The radio transmitter assembly is operative to modulate and frequency translate a plurality of input information-bearing signals. The signals are then combined to form a first FDM signal, which can then be routed to the transmitter subassembly via a single FDM cable running up the tower. The transmitter subassembly includes a power splitter for splitting the first FDM signal into a plurality of second FDM signals and a plurality of frequency translators, each for frequency translating one of the second FDM signals. Each frequency translator thereby places at least one of the information-bearing signals within a predetermined translated frequency band.

Abstract: A power amplifier output module 200 having low insertion loss and self-shielding properties for dual-mode digital systems is provided. Module 200 has a first power amplifier drive circuit comprising a first power amplifier 220 and a first output impedance matching network having integrated suppression of higher order harmonics 222. A second power amplifier drive circuit comprising a second power amplifier 224 and a second output impedance matching network having integrated suppression of higher order harmonics 226 is also provided. Module 200 also comprises a single diplexer 228 coupled to the first impedance matching network and the second impedance matching network. Module 200 also comprises a single broadband directional coupler 230, coupled to the diplexer 228, for coupling both the first power amplifier drive circuit and the second power amplifier drive circuit. Module 200 provides an integrated solution involving greater performance in a smaller package.

Abstract: A satellite payload having d transparent channels, a first plurality d of band-pass channel filters IMUX of bandwidth .delta. that filter received signals, frequency converters, a plurality k of channel amplifiers (k.gtoreq.d), power amplifiers and a second plurality p of channel filters OMUX that filter the signals amplified by the channel amplifiers and the power amplifiers, d amplifiers assigned to said d channels, the frequency converters including at least one mixer and at least one source of a conversion frequency signal, wherein the g band-pass channel filters IMUX filter the received signals before frequency conversion by the converters.

Abstract: A multi-channel transmit amplifier array comprising a multiplicity N of coupled power amplifier elements is disclosed. The number of channels provided for amplifying desired signals for transmission is less than N, by at least one. In this case, the unused channel is used to inject an intermodulation compensation waveform specifically tailored to reduce intermodulation generated in all of the other N-1 signal paths. Instantaneous complex waveform values for the intermodulation compensation waveform may be systematically computed from the instantaneous complex values of the N-1 desired signals in such a way as to minimize the greatest signal amplitude in any of the N signal paths.

Abstract: A field programmable tracking device which includes a programmably channelized multichannel transmitter. The transmitter includes a magnetically operable circuit which allows external programmability of transmission channel selection. Activation of the magnetically operable circuit for a first period of time activates a microcontroller. Continued activation of the magnetically operable circuit for a second period of time causes the microcontroller to initiate a verified channel count. Once a desired channel count is verified, activation of the magnetically operable circuit is stopped to select the desired channel. The transmitter is provided with a flexible antenna. Both the transmitter and the flexible antenna can be coupled to a collar.

Abstract: A two-way communication system for communication betweeen a system network and a mobile unit. The system network includes a plurality of base transmitters and base receivers include in the network. The base transmitters are divided into zonal assignments and broadcast in simulcast using multi-carrier modulation techniques. The system network controls the base transmitters to broadcast in suimulcast during both systemwide and zone boundaries to maximize information throughout. The preferred mobile unit inlcudes a noise detector circuit to prevent unwanted transmissions. The system network further provides an adaptive registration feature for mobile units which controls the registration operation by the mobile units to maximize information throughout.

Abstract: A multi-channel transmitter (200) in accordance with the present invention overcomes the disadvantages of applying adaptive antenna array technology to multi-channel communication systems. The multi-channel transmitter includes a channel processing element (210), a plurality of radio frequency processing elements (206), and an antenna array (102). The channel processing element includes a channel processor adapted to receive a communication signal from a communication network, a splitter (216) coupled to an output of the channel processor for producing a plurality of substantially identical processed digital communication signal outputs. A plurality of gain and phase adjusters (214) in the channel processing element are coupled to the substantially identical processed digital communication signal outputs. An output of each phase and gain adjuster (214) is coupled to a plurality of up-converters (212), which each produce a digital intermediate frequency output.

Abstract: A transceiver board for use in a cellular radiotelephone base station comprises a first cellular radio transceiver including a first controller that controls the operation of the first transceiver, a second cellular radio transceiver including a second controller that controls the operation of the second transceiver, common local oscillator that generates a tuning signal used by the first and second transceivers for tuning a radio signal, and an arbitrator that is connected to the first and second controllers and that determines which of the first and second controllers communicates with the common local oscillator. Preferably, the arbitrator is implemented by a programmable device such as a programmable logic device (PLD) that monitors the first and second controllers to determine which controller attempts to communicate with the common local oscillator first so that that controller is allowed to communicate with a common local oscillator to the exclusion of the other controller.

Abstract: A multi-band mobile station (10) includes a plurality of RF amplifier sections, one for each frequency band of interest; a controller (18) for selectively enabling, when transmitting, only one of the RF amplifier sections; a directional coupler circuit for detecting the power of an amplified RF signal that is output from the enabled one of the RF amplifier sections; and a single error detection circuit, coupled to the detecting circuit, for generating an error signal. The error signal has a magnitude that is indicative of a difference between the detected power and a desired power. The error signal is coupled to the enabled one of the RF amplifier sections so as to minimize the magnitude of the error signal. The controller may place a non-enabled RF amplifier section into a low power consumption mode. The directional coupler circuit includes an RF detector coupled to the directional coupler, and an impedance matching circuit coupled between the directional coupler and the RF detector.

Abstract: The present invention is a digital FM voice paging system which uses digital signal processing (including D/A conversion and data compression) to transmit voice pager data over existing FM broadcast subcarrriers.

Abstract: An RF transceiver operable in two separate frequency bands has transmitter and receiver elements with broadband components to provide a flat frequency response across the two separate operating frequency bands. The broadband transmitting and receiving elements are utilized with other narrow band components which are designed for operating in either the first frequency band or the second frequency band. The use of common components for operating in both frequency bands reduces part count and cost along with reduced size and weight.

Abstract: A multiplicity of baseband input signals are supplied to a signal processor which functions to modify the input signals such that when the modified signals modulate corresponding multiple carrier wave signals which are combined to produce a composite signal which is applied to the input of an amplifier, the "peaking" at the input to the amplifier and the resultant intermodulation at the output of the amplifier are reduced. In response to the application of the baseband input signals, the signal processor determines the extent of peaking and modifies at least one of the phase and amplitude of the input signals. In one embodiment of the invention, a block of data representing the input signals over a time slot is supplied to the signal processor which then generates a fixed phase shift over the time slot. In another embodiment of the invention, a block of data representing input signals is applied to a signal processor which then determines the worst case peaking and the time of their occurrence.

Abstract: A time diversity transmission-reception system has, on transmit side, at least one delay of a predetermined delay for providing at least a pair of delayed and undelayed data symbol sequences, at least a pair of modulators for modulating the data symbol sequences into modulated intermediate frequency signals, and at least a pair of spread spectrum signal generators employing mutually different pseudo-random code sequences for code division multiplexing. On receive side, the received signals are subjected to code division demultiplexing, demodulation, and delaying to restore at least a pair of timed demodulated signals. These signals are then subjected to adaptive matched filtering, whose outputs are combined and applied to adaptive equalization to provide diversity reception signal. The present system provides a plurality of diversity branches without employing a plurality of frequencies, planes of polarization of a carrier wave or receiving antennas.

Abstract: A multiple access digital up converter/modulator includes selectors (1606, 1608) having inputs (1602, 1604) and outputs coupled to first and second interpolating filters (1610, 1626). The output of the first interpolating filter is selectively coupled to a first mixer (1612) and a first adder (1622), the first adder also receiving a first phase value and the output is coupled to a first phase accumulator (1616) the output of which is coupled to a first sinusoid generator (1614) and selectively coupled to a second sinusoid generator (1630). The output of each of the first and second mixers are selectively coupled to an output adder (1634) and to inputs of the first and second mixers. The output of the second interpolating filter (1626) is selectively coupled to a second mixer (1628) and a second adder (1638), which also receives a second phase value and the output of which is coupled to a second phase accumulator (1640) the output of which is selectively coupled to the second sinusoid generator.

Abstract: A device that communicatively couples a number of transmitters and receivers to a number of antennas. The device includes transmit ports each of which may be connected to a respective transmitter, receive ports each of which may be connected to a respective receiver, and antenna ports each of which may be connected to a respective antenna. One coupling unit has inputs connected to each transmit port and outputs to respective antenna ports for combining individual transmit signals received at each transmit port to form a combined transmit signal, and outputs the combined transmit signal to each respective antenna port. A second coupling unit has inputs connected to respective antenna ports and outputs to each receive port for combining individual receive signals from each respective antenna port to form a combined receive signal, and outputs the combined receive signal to the receive ports.

Abstract: The invention provides a method and apparatus for transmitting digital signaling formation to a receiver using a plurality of antennas. The invention involves applying a channel code to a digital signal producing one or more symbols. A plurality of symbol copies is made and each copy is weighted by a distinct time varying function. Each antenna which are located at two or more base stations transmits a signal based on one of the weighted symbol copies. Any channel code may be used with the invention, such as a convolutional channel code or block channel code. Weighting provided to symbol copies may involve application of an amplitude gain, phase shift, or both. The present invention may be used in combination with either or both conventional interleavers and constellation mappers.

Abstract: A method and apparatus for transmitting digital sound is disclosed. The method contemplates transmitting a digital radio signal (such as an FM band signal) over a plurality of sub-channels subject to some constraints on the digital signal power. A control sub-channel, sometimes referred to as an auxiliary overhead channel is used to transmit control information which is interpreted by the receiver to identify the location and potentially the mode of the digital signals.

Abstract: An original data signal is transmitted by a predetermined transmission power, the data signal distorted during transmission is received, and the received signal is output after being restored to the original data signal, the SNR for each subchannel is calculated and a higher power is allocated to a subchannel having a higher SNR and a lower power is allocated to a subchannel having a lower SNR. If the transmission power of each subchannel exceeds a maximum limit, the maximum limit is redetermined as the transmission power of the subchannels whose transmission power exceeds the maximum limit. Then, the transmission power of a subchannel whose SNR is negative is determined if the transmission power of each subchannel does not exceed the maximum limit or the above redetermination step is completed. Thereafter, the transmission power of each subchannel is controlled to the determined power.

Abstract: A beam steering array that comprises a high voltage source for providing high voltage pulses and a plurality of high voltage switches coupled between the high voltage source and a plurality of microwave sources. Each of the microwave sources are coupled to an antenna element. A trigger source is coupled to the plurality of high voltage switches for providing trigger pulses thereto that are used to selectively switch the respective switches on and off to transfer the high voltage pulses from the high voltage source to a selected microwave source. In a reduced to practice embodiment, the present invention provides for a thyratron switched beam steering array comprising a plurality of channels that each include a high voltage switch comprising a thyratron, a triggering circuit, a magnetron that is used as the microwave source, and an antenna element coupled to the magnetron.

Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Abstract: A radio communication system and method for minimizing co-channel interference comprises a technique for communicating between first stations and second stations.

Abstract: A transmission power control apparatus in a communication apparatus which synthesizes IF signals output from a plurality of channel units and emits the synthesized signal from an antenna. In the transmission power control apparatus, when none of channel units transmit an IF signal, a controller changes the connection of a power amplifier from the antenna over to a dummy antenna and supplies the output of the power amplifier to the dummy antenna, and instructs a predetermined number m of channel units to output IF signals, a reference voltage generator generates a reference voltage corresponding to a transmission wave number m, and a variable attenuator or a variable amplifier controls gain so that the difference between detected voltage corresponding to a transmission power and the reference voltage becomes zero.

Abstract: A land mobile radio system (110) includes a plurality of radio channels (112), each radio channel (112) being interconnectable (115) to any one of a number, N, of combiners (114), and each combiner (114) being associated with a corresponding transmit antenna (120). A combiner output signal at the output of each combiner (114) is connected to a transform matrix (133) which divides each combiner output signal into a number, N, of transformed signals, each transformed signal containing an equal power level part, 1/N, of each combiner output signal. Each transformed signal is provided to an amplifier (135) for amplification thereof, and the amplified transformed signals are provided to an inverse-transform matrix (138) which recombines the equal parts of each amplified transformed signal into amplified combiner output signals which are provided to the antennas (120) for transmission thereof. The land mobile radio system (110) includes N antennas (120), and where N is a power of m, e.g., N=m.sup.

Abstract: Disclosed is a method for operating a communications signal transmitter and apparatus for carrying out the method. The method includes the steps of receiving a communications signal; sensing a signal strength of the received communications signal, the signal strength being indicative of the current user demand; adjusting an output of a power supply that supplies operating power to a communications signal transmitter amplifier in accordance with the sensed signal strength so as to increase the output of the power supply when the sensed signal strength increases and to decrease the output of the power supply when the sensed signal strength decreases; and amplifying the received communications signal with the communications signal transmitter amplifier. The step of sensing may include a step of subtracting a noise component from the received communications signal.

Abstract: In multiple-channel microwave transmitters and communications systems, such as multi-point video distribution systems operating at frequencies of around 29 GHz or 40 GHz, good frequency stability for each of the channel frequencies is achieved with a feed-back loop including an error detector circuit. The error detector circuit (39,29) is coupled between a sampler and an input circuit of the source. This detector circuit detects any drift or other error in the carrier frequency of the sample from the desired microwave frequency for that channel signal and provides a corrective signal to the input circuit. The part of the feed-back loop comprising at least a part of the detector circuit is common to a group of the channels. Switch means couple the common part of the feed-back loop between the sampler and the source input circuit of each channel, and so permit this common part to be time multiplexed between the respective feed-back loops of the group of channels.

Abstract: A new system for allowing PCS Providers to share cell sites, and more particularly multi-sector antennas, is provided. The present invention utilizes primarily passive, linear components to combine the transmit signals of PCS Providers which reside in non-adjacent frequency bands over a multi-sector antenna and to distribute from a multi-sector antenna the receive signals in all frequency bands of the PCS Providers.

Abstract: An adaptive transmitting antenna includes an array of antenna elements having respective weighing coefficients to respectively transmit components of a transmit signal which reduces locally reflective multipath signals received by the transmitting antenna to sample respective reflective components which are summed and cross correlated to a time delayed transmit signal to produce a correlated output indicative of the reflective signal strength. The correlated output is minimized by adjusting the weighing coefficients so that the transmit signal has reduced multipath distortions. The adaptive technique is well suited for mobile telephone transmitters moving about objects tending to reflect and distort transmitted signals.

Abstract: An amplifier with adaptive output capacity allocation (201) including a processor (203), coupled to a signal, for examining the signal to determine a first capacity requirement and a second capacity requirement, and an amplifier (213), coupled to the processor and the signal, for processing the signal in accordance with the first capacity requirement and the second capacity requirement to provide an output signal thus maximizing power out of the amplifier given incoming signal conditions.

Abstract: A method an apparatus for controlling frequency of a multi-channel transmitter. A reference frequency is generated and emitted to a thermally stable frequency discriminator. The thermally stable frequency discriminator emits a dc voltage to a plurality of individual oscillators. The individual oscillators in continuous wave mode or modulated by baseband signals are combined into a multi-channel signal at an intermediate range of frequencies. The multi-channel intermediate range of frequencies are preferably amplified and emitted as an output signal. At relatively lower frequencies, such as 4-6 GHz, up-conversion of the output signal is not necessary. At relatively higher frequencies, an up-converter can be used to employ a second thermally stable frequency discriminator.

Abstract: The present invention discloses a hub and remote cellular system having RF generating equipment located at a centralized hub, and RF front end equipment located at each of a plurality of remote omni-directional cell sites. The centralized hub distributes channels for the remote cell sites. The hub and remote structure provides for the efficient allocation of resources to a plurality of cell sites, lowers equipment costs, real estate costs, regulatory costs, and maintenance costs.

Abstract: A radio frequency manager (12) for choosing a selective call transmitter (20 or 25) among a plurality of selective call transmitters comprises a memory (13) for storing historical data on messages previously sent, the historical data comprising for each transmitter at least a latency measurement and a message queue profile and another memory (15) for storing pending messages, each of the pending messages having current information comprising at least an associated priority for the pending messages. The radio frequency manager further comprises a sorter (21) for classifying the historical data and the current information using fuzzy logic, wherein the sorter comprises a fuzzifier (14) for generating membership values, a rule base (16) for applying a set of predetermined rules to the current input conditions to perform a mapping with the historical conditions, and a defuzzifier (18) for generating a non-fuzzy prediction recommendation from the mapping for recommending the optimum transmitter.

Abstract: A modular interconnect matrix (200) interconnects a plurality (M) of radio channel units (203) with a plurality (N) of antennas (202). Each radio channel unit (203) is connected to a first connector (222) on a corresponding first switching module (217) having a plurality (N) of seconds connectors (225). Each antenna (202) is connected to a first connector (212) of a corresponding antenna interface module (205) having a plurality (X) of second connectors (215). The second connectors (215,225) on the modules (205,217) are arranged for interconnection of at least one second connector (225) on each of the first switching modules (217) with at least one second connector (215) on each of the antenna interface modules (205).

Abstract: The invention involves a method of transmitting a control signal that is synchronized in time with a radio program signal. The control signal may be used, for example, in a receiver to restore dynamic range reduction that occurred at the transmitter. The method includes the steps of forming a first supplemented signal by inserting the control signal and a first time-reference signal into a data stream of a radio data signal such as an RDS signal. A second supplemented signal is formed by adding a second time-reference signal to the radio program signal. The first and second time-reference signals are correlated in time. The first and second supplemented signals are transmitted.

Abstract: An apparatus and method for controlling a final transmit power, y, of a base station in a cellular communications system that has several channels. The base station has a transmit power tracking gain, y', and a radio frequency transmit power, w. The apparatus comprises channel elements for calculating expected powers, P.sub.k,a -P.sub.k,i, each of which corresponds to a channel. The apparatus also comprises a transceiver system controller (BTSC) for generating a desired output power, y.sub.d, of the base station, including an adder for summing the expected powers. The apparatus also includes a transmit power detector for measuring y to obtain a measured transmit power. The apparatus further comprises a radio frequency interface card (RFIC) for generating y'. Finally, the apparatus includes a gain unit for processing y' and w to obtain the final transmit power, y.

Abstract: An apparatus (10) for adjusting peak-to-average power of a multicarrier signal. The apparatus (10) comprises a first (26) and second (28) combiner, a phase-changing device (30), and a switch (36). The first combiner (26) receives a first group of channels (20) and a second group of channels (22) and produces a first combined signal (46). The phase-changing device (30) receives the first group of channels (20) and produces a group of phase-adjusted channels. The second combiner (28) receives the phase-adjusted channels and the second group of channels (22) and produces a second combined signal (48), and the switch (36) responds to the first (26) and second (28) combiners and selects at least one of the first (46) and second (48) combined signals.

Abstract: A modular interconnect matrix (200) interconnects a plurality (M) of radio channel units (203) with a plurality (N) of antennas (202). Each radio channel unit (203) is connected to a first connector (222) on a corresponding first switching module (217) having a plurality (N) of seconds connectors (225). Each antenna (202) is connected to a first connector (212) of a corresponding antenna interface module (205) having a plurality (X) of second connectors (215). The second connectors (215,225) on the modules (205,217) are arranged for interconnection of at least one second connector (225) on each of the first switching modules (217) with at least one second connector (215) on each of the antenna interface modules (205).

Abstract: A summing network for combining and feeding radio frequency signals supplied by radio transmitters to common antenna means, includes conductors, connectors and a stub. In order to make the tuning of the summing network easier, the stub includes a changer for changing the electrical length of the summing network as a response to a control signal fed to the stub.

Abstract: In a remote-control communication system, a signal generating unit includes a first signal transmitter for transmitting a first signal at a first frequency, such as UHF, a second signal transmitter for transmitting a second signal at a second frequency, such as an infrared frequency, that is diverse from the first frequency; a keyboard for generating an information signal containing a given message, which is modulated onto both the first signal and the second signal; wherein both the first and second modulated signals are transmitted in response to a key of the keyboard being pressed to generate the information signal. A receiver for the system includes a microcontroller for processing the given message to control a given operation of an electronic communication apparatus; a UHF detector and demodulator unit and an infrared detector and demodulator unit, which respectively detect and demodulate the first and second modulated signals to provide the information signal containing the given message.

Abstract: A method and system for using a low-cost, fixed output power radio in a multi-carrier communication system is disclosed herein. This system measures the output power of the multiple channel units within the system, obtains the current output power of the system, calculates a composite power and an expected power, compares the expected power and the current output power to calculate a gain adjustment value, and adjusting the output power of the system via the amplifier. The method for adjusting the power can also allow at least one of the carriers in the multi-carrier system to operate in a burst mode, and at least one of the remaining carriers to operate in a continuous mode during power measurement and gain adjustment steps.

Abstract: A method of multicarrier modulation using co-located transmitters to achieve higher transmission capacity for mobile paging and two-way digital communication in a manner consistent with FCC emission mask limits. Co-location of the transmitters obviates the need for stringent, symmetrical subchannel interference protection and provides for a wider range of operating parameters, including peak frequency deviation, bit rate, and carrier frequencies, to obtain optimal transmission performance.

Abstract: A method is disclosed for using feedback to reduce crosstalk between mobile receivers in a wireless communications system comprising an adaptive transmitting antenna array. Feedback signals from the receivers are time-averaged and used to calculate a set of weight vectors that minimize crosstalk and maximize desired signal without requiring burdensome feedback rates. Beamforming diversity is combined with feedback through the use of diversity vectors. The preferred embodiment includes a method for obtaining the required feedback by exploiting the SAT circuitry present in the AMPS system currently in use. Consequently, the method may be implemented without modification to existing cellular phone handsets.

Abstract: The invention provides a means by which a radio system in a multipath propagation environment may improve the probability of successful reception of a message by the application of diversity. It is applicable to such applications as paging, cordless telephones, cellular telephones, and radio identification tags. The transmitter sends the message repeatedly, each repetition transmitted from a different antenna. The antennas are separated so that multipath fading of the signal arriving at the receiver from each transmit antenna is substantially uncorrelated with the multipath fading of the signal arriving at the receiver from the other transmit antennas. The receiver examines the radio channel for an incoming message for a time period long enough for it to potentially receive the message from each antenna.

Abstract: A radio module for a radio base station of a mobile radio system which transmits and receives radio signals from stationary or moving mobile radio stations over given frequencies. A module comprises an antenna part and a transceiver part of given mechanical construction. Each module of a base station transmits and receives over a given specific frequency which may be different when transmitting and receiving but which is not the same frequency as that used by any other module in the station. A radio base structure is comprised of a plurality of modules, each having its own specific or individual transmitting and receiving frequency and being provided with suppression means which prevent a module from disturbing neighboring modules. A radio base structure having diversity reception is also provided.

Abstract: A radio communication apparatus comprises a first/second modulator for modulating a first/second signal according to a first/second frequency, a first demodulator for detecting the received first modulation signal and regenerating the carrier, a clock regenerator for regenerating a clock from the detection output from the first demodulator, an amplitude sampler for sampling the amplitude of the received first modulation signal according to the regenerated clock, a second demodulator for controlling the frequency of the received second modulation signal and executing demodulation for the signal, and a gain controller for executing gain control for the output from the second demodulator according to the output from the amplitude sampler.

Abstract: An antenna for a base station comprising a plurality of antenna arrays (40; FIG. 6a) each capable of forming a multiplicity of separate overlapping narrow beams in azimuth, the arrays being positioned such that the of beams formed by the arrays provide a coverage in azimuth wider than each array. Means are provided for recognizing unique identifier signals (70; FIG. 6b) incorporated in call signals passing through the antenna; and coherent detection means for discriminating between unwanted call signals and wanted call signals using said unique identifier signals.

Abstract: A satellite switching network disposed to operate with relatively few redundant components. The high-frequency switching network with improved routing architecture (10) of the present invention is operative to convert input signals received over a plurality of receive channels into output signals to be carried by a plurality of transmit channels. An arrangement of receiver networks 104, 106, 108 and 110 converts the input signals to a plurality of intermediate frequency (I.F.) signals. The I.F. signals are routed to a set of synthesized downlink transmitter networks 186, 190, 192, 194 by a switch matrix 126. Each synthesized downlink transmitter generates signal energy over a set of downlink channels in response to the I.F. signals supplied thereto.

Abstract: A method and a device for supervising the condition of an antenna by measuring the ratio of the magnitude of a transmitted signal to the magnitude of a signal reflected from the antenna and by using, in addition to fixed alarm limits, an adjustable alarm limit, by which the condition of the transmitter device can be found out.

Abstract: A system (10) for combining a plurality of transmission channels within a multiple channel communication system includes a master computer (20) that controls the transmission frequency and schedule of a plurality of channel transmitters (18). Each channel transmitter (18) is electrically connected to a channel transmitter combiner filter (12). Each channel transmitter combiner filter (12) is fixedly tuned to a unique bandwidth window along the electromagnetic spectrum, and two sets (24), (26) of channel transmitter combiner filters are formed of the channel transmitter combiner filters (12) whose unique bandwidth windows are adequately spaced for electrical isolation along the electromagnetic spectrum. Each set (24), (26) of channel transmitter combiner filters is electrically connected to a common antenna (28) by means of a three decibel (3 dB) coupler (22).

Abstract: A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Abstract: A communication base station system for transmitting data to a movable body includes a plurality of transmission sections, each of the transmission sections receiving a transmission data, modulating this received transmission data, and then converting the frequency of this modulated transmission data to a preset frequency and outputting a result. A control section monitors a status of use of the transmission sections, and if having confirmed at least two transmission sections that do not transmit any data, the control section outputs a specified signal instead of the transmission data to two transmission sections among the confirmed transmission sections. An amplification section collectively amplifies a plurality of output signals from the transmission section and a compensation circuit compensates for intermodulation distortion components generated in the amplification section based on an output of a transmission section that has received the specified signal and its respective transmission frequency.