Abstract: A wristwatch paging receiver is provided with an antenna matching network that automatically retunes the network at the beginning of a listening interval. During the retuning operation, a control signal is applied to a variable tuning element in the matching network, such as a varactor diode, and is swept from a minimum value to a maximum value. This sweeping is desirably performed in discrete voltage steps that correspond to unit increments of varactor capacitance. A feedback signal from the receiver, such as an AGC signal, is monitored during this operation to note which varactor bias signal yields the maximum AGC signal. After the sweep is concluded, the apparatus applies to the varactor the bias voltage that yielded the maximum AGC signal during the sweeping operation. This bias voltage is maintained through the end of the listening interval. At the beginning of the next listening interval, the process may be repeated.

Abstract: A central controller of a communication system network may more efficiently expand an audience of a communication in the following manner. When a communication unit of a first communication group within a first communication system transmits a request for service, the central controller determines whether the audience of that predetermined communication is to be expanded. When the audience of the predetermined communication is to be expanded, the central controller combines at least part of at least one other communication group with the first communication group based upon a predetermined grouping arrangement. Having combined the groups, the central controller processes the predetermined communication among the communication units in the first communication group and the communication units in the at least part of the least one other communication group.

Abstract: A double super-heterodyne tuner provided with an up-converting section and a down-converting section, and including an input filter constituted by single tuning to be supplied with an input signal, an RF amplifier for amplifying the signal passing through the input filter, and an inter-stage tuning circuit constituted by single tuning connected to an output end of the RF amplifier and provided at an input portion of the up-converting section. The input filter and the inter-stage tuning circuit are supplied with a tuning voltage different from that supplied to a first local oscillator so as to alter its filter characteristics for simplification of the circuit construction and improvement of NF (noise factor).

Abstract: A radio or speaker-microphone unit includes a housing having first and second portions. A speaker is disposed in one of the portions and a microphone in the other of the portions. The portions are movable between first and second relative positions, with one of the positions providing a handset configuration and the other providing a speaker-microphone configuration. A switch senses the relative position of the housing portions and adjusts the gain of an audio amplifier.

Abstract: A broadcast and reception system provides a segmented broadcast signal for providing regional traffic information and a receiver adapted to receive selected segments of that broadcast. The segmented broadcast signal includes a number of segments which each include a tone sequence, a digital regional code, a digital duration code, and an audio segment. The receiver monitors selected regional traffic segments and converts the selected audio segment to a form compatible with a standard automotive radio. Thus, a user can selectively monitor regional traffic information without having to listen to reports from regions of no interest to him. Alternatively, the selected traffic information can automatically override normal radio listening.

Abstract: A method for providing a positive transmitter power switch-on in a dual-mode mobile phone is disclosed. According to the invention the transmitter is switched on in two or more phases, controlled by the mobile phone microprocessor program. Preferably the power amplifier sections are switched on in a sequence, so that the output power amplifier sections (3 and 4) are first switched on by enabling the transmit enable signal (TXE). Then the input power amplifier sections (1 and 2) are switched on by enabling ramp-up signal (RAMP-UP) Transmission is thereafter enabled by the transmit power control signal (TXC) being switched on, the amplifiers then output the amplified radio frequency input signal (RFIN) to the duplex circuit (10) transmit terminal (TX).

Abstract: A digital radiotelephone system requiring a transfer of communication from a source base-site (200) in a source cell (100) to a selected one target base-site in a target cell. A source base-site (200) in the source cell (100) provides a first and a second threshold and measures the received signal strength of a mobile unit (225) communicating to the source base-site (200). When the measured signal strength at the source base-site (200) falls below the first threshold, the source base-site (200) initiates a handoff to target base-sites located by the mobile unit (225). The target base-sites measure the received signal strength of the mobile unit (225) and a target base-site is selected. The source base-site (200) is notified of the selected target base-site and hands off communication of the mobile unit (225) to the selected target base-site when the previously measured signal strength at the source base-site (200) falls below the second threshold.

Abstract: A site architecture for a trunked radio frequency communications system provides better fault tolerance capabilities than are available from architectures including redundant hardware. During normal system operations, a primary site controller performs most or all system control functions while signal processing functions are performed in a distributed manner by trunking cards associated with individual repeater channel receivers and transmitters. In the event the site controller fails, the trunking cards also begin performing trunking and other control functions. The trunking cards cease attempting to communicate with the failed site controller, and begin communicating directly with one another via a high speed backup serial link.

Abstract: The radio unit of a modern radio telephone comprises a plurality of controlled two-position switches. Each controlled switch most often requires an individual control line from a processor. The greater the number of controlled switches in the circuit, the more control lines that are needed. The number of control lines is substantially reduced in that from one or several control lines of a frequency synthesizer in the radio unit, a switch line is branched off for the controlled switches. During the time in which the synthesizer circuit receives no control signals, the logic unit of the radio telephone supplies a control voltage to the controlled switches over a control line of the synthesizer and over a switch line branched therefrom.

Abstract: A diversity repeater that incorporates diversity diagnostic circuitry. The diversity diagnostic circuitry monitors the outputs of at least two receivers and determines the signal strength of the transmissions received by each receiver. If the signal strength for a particular receiver is below a predetermined threshold, the diversity diagnostic circuitry determines whether that receiver is receiving a rayleigh faded transmission or is an inoperative mode.

Abstract: A dual in-band/out-of-band CATV receiver includes a coupler that couples input signals to a tuner and decoder for demodulation and recovery of in-band data and to an FSK receiver for recovery of out-of-band data. The recovered data outputs of the decoder and of the FSK receiver are coupled to a data switch that has a common output that is coupled to a tuner/decoder microprocessor. The tuner/decoder microprocessor in turn supplies information to a switch microprocessor for controlling operation of the data switch to couple either in-band or out-of-band data to the tuner/decoder microprocessor. The data switch defaults to the in-band data position whenever a channel change occurs.

Abstract: In a mobile cellular radio system, load balancing is achieved by moving dynamically the borders between any two cells such that an overloaded cell becomes smaller and the neighboring cell larger. This is achieved by lowering the entering signal strength threshold for handoff to the neighboring cell and/or increasing the entering signal strength threshold for handoff from the neighboring cell. Thresholds are unique for any two cells.

Abstract: The molded key switch shield assembly (100) includes a molded member (104) and a key switch overlay (102). The molded member (104) includes a shield metallization pattern (136) which substantially covers major portions of both the first (138) and second major surfaces (140) of the molded member (104). The molded member also includes a metallization pattern (124) having a plurality of key switch locations (118) which can be shorted by conductive locations (112) on key switch overlay (102).

Abstract: A communication system (10) comprises a portable radio (20) and a plurality of mobile repeaters (12), a mobile repeater system 200 comprising a portable signal receiver (224) for receiving portable radio signals; a mobile transmitter (218) for transmitting the portable radio signals received by the portable receiver; a mobile receiver (226) for monitoring mobile transmissions; a delay state counter (202) for delaying the transmission of the portable radio signals received; and a received signal strength indicator (204) for determining the strength of received mobile radio signals, the received signal strength indicator being coupled to the delay state counter, via a controller (206), for decrementing the delay state counter when the mobile receiver does not detect a mobile transmission having at least a predetermined received signal strength level.

Abstract: A method of synchronizing a plurality of remote site transmitters (200) in a digital simulcast transmission system is described that enables use of four-level modulation on two-level modulation systems. A synchronization signal is transmitted at a predetermined data rate from a prime site, which signal might include a synchronization pattern having a first and a second portion. The first portion of the synchronization pattern is used for synchronization, while the second portion indicates the completion of the first portion. The method includes detecting (205, 320) of the first portion of the synchronization pattern. Each remote site transmitter (200) further has a modulation clock having a phase polarity which is selected (215, 324) in response to the detection of the first portion of the synchronization signal.

Abstract: A method and device are set forth for providing improved diversity reception to a receiver system in a communication system, the receiver system having at least one receiver on each of at least a first and a second receiver branch. The method and device provide, upon receipt of signals on the receiver branches, for utilizing received signal strength voltages to determine control voltage values, utilizing the control voltage values to amplify the designated signal (the designated signal being, for example, a signal having a received signal strength (RSSI) greater than a predetermined threshold) to obtain an amplified designated signal, and generating a resultant signal in view of the at least first amplified designated signal. The control voltage values are utilized to obtain at least one weighted difference. The at least one weighted difference is utilized to obtain an adjusted amplification of the at least one designated signal in accordance with a linear approximation.

Abstract: When communication is established using a mobile radio terminal, the speed at which the terminal is moving is measured by monitoring the Rayleigh fading of the signal strength. Using this velocity indicative parameter, a threshold level which is used to determine if a handoff is required or not, can be adjusted in a manner which renders the decision process more accurate and minimizes the number of unwarranted handoffs.

Abstract: The substrate for implementation of MMIC devices comprises alumina with feedthrough holes drilled therein to provide conduct ion paths from the top surface of the substrate to the bottom surface. A high-temperature to low-temperature fabrication process is used to form circuit traces and components upon the substrate. Each of the thick film deposition processes is followed by a firing process to remove organic materials from the deposited material and to secure the material to the substrate or previous layer. A Ku-band transceiver constructed using the process includes the attachment of six discrete, unpackaged MMIC's and one HEMT. All other devices and traces are patterned on the substrate and the discrete components are directly attached to pads on the substrate.

Abstract: A method and apparatus for achieving reliable transmission of signalling messages in a cellular system in which the frequency plan, frequency/time slot allocation plan, code channel allocation plan, or dynamic/adaptive channel allocation rule of the system is violated by allowing adjacent base stations to reuse particular frequencies/time slots/channels for signalling a particular mobile station. In situations where signalling messages, such as handoff commands, which are communicated between a base station and a mobile station are not properly received by the mobile station, an alternate communications channel will be established to ensure the reception of these messages. The alternate channel is provided by repeating the message through a channel associated with a base station which has better radio characteristics. The channel selected for transmission of the message by the new base station will be on the same frequency/time slot/code as used by the established connection.

Abstract: A communication installation for use in a site having underground galleries, for information exchanges, comprises a repeater connected to a wired distribution network. The repeater is arranged for receiving messages which arrive over the wired network at a first frequency and for retransmitting the messages over the network at a second frequency different from the first frequency. The network comprises non-radiating cable sections, radiating cable sections capable to radiate at the second frequency and to collect radiation energy at the first frequency from a portable emitter-receiver set placed nearby. The network further comprises terminal antennae for emitting at the second frequency and collecting energy at the first frequency.