Abstract: A circuit for saving battery power in a radio paging receiver having a process for supplying first and second power saving signals indicative of first and second ON and OFF power signals. A first radio-frequency section converts the received radio-frequency signals upon reception of the first ON power signal; a second radio-frequency section then filters and demodulates the output signals from the first radio-frequency section to provide demodulated signals having a first voltage upon reception of the second ON power. A waveform shaper shapes the waveform of the demodulated signals to provide digital signals to the processor upon reception of the second ON power signal; and a switch enables and disables transmission of the first and second ON and OFF power signals from a power source to the first and second radio-frequency sections and the waveform shaper upon reception of the first and second power saving signals.

Abstract: A location signalling device sends a radio distress call giving the precise location coordinates of a person in distress automatically once it is activated without the need for anyone to operate an associated radio transmitter. The device includes a microprocessor controller, a digital location data input, a keyboard, a voice input, an LCD display, a clock/timer, a digital memory, and a voice synthesizer output which provides the distress call in audio voice signals to the microphone input of the radio transmitter when an activating switch is pressed.

Abstract: The center frequency of each of the analog filters with different selectivities each other installed in an automatic adjusting circuit is automatically adjusted in accordance with a bias input signal which is generated by the phases detectors respectively associated with the analog filters in accordance with a frequency difference, so as to be equal to the reference frequency of an input signal applied to the two analog filters. The bias input signal is fed to an analog filter to be controlled, which is formed on the same chip as that of the above two filters. A coarse adjustment is based on the output signal of the phase detector associated with the analog filter with a low selectivity. A fine adjustment is based on the output signal of the phase detector associated with the analog filter with a high selectivity.

Abstract: A receiving apparatus according to the present invention comprises a high frequency amplifying circuit for amplifying a signal received from an antenna by a gain in accordance with a control signal, a frequency conversion circuit for converting the output frequency of the high frequency amplifying circuit, a narrow band filter for selectively passing therethrough the intermediate frequency signal components of the output of the frequency conversion circuit, and control signal generating circuit for generating a control signal in accordance with the output level of the frequency conversion circuit. The control signal generating circuit is so constructed that the control signal generating circuit outputs the control signal only when the output signal level of the frequency conversion circuit is higher than a level in accordance with the level of the narrow band filter.

Abstract: A linear amplifier comprising a feedback loop is stabilized by determining phase error between an error signal and a feedback signal and shifting the phase of a forward signal accordingly.

Abstract: To analyse its spectrum, a radio signal is beat with an intermediate signal in a heterodyne circuit having a local oscillator sweeping a range of intermediate frequencies. The oscillator signal also beats with the output from a comb generator to produce signals marking intervals in its frequency sweep. The magnitude of the filtered intermediate frequency signal is measured between intervals marked by the frequency interval signals to output a frequency spectrum of the input signal. Preferably, the intermediate frequency signal is filtered in a homodyne demodulating unit employing a further local oscillator tuned to the intermediate frequency. A spectrum data display employs a memory storing the signal magnitudes at successive frequency steps at respective addresses associated with individual frequency steps. The magnitude values are assigned to their addresses by the spectrum frequency interval signals.

Abstract: The process of the present invention first synchronizes to incoming messages from the base station. The first data word is received and stored in the radiotelephone. The error code in the data word is next checked to determine if errors exist in the word. If there are errors, the word is corrected. This process is repeated on another data word and the second received word is compared with the first. If the words are not equal, the receiver remains on until at least two words are equal or the entire length of the message is received. If the words are equal, the word is processed by the radiotelephone and the receiver is turned off for the remaining portion of the message until the next synchronization word is to be received.

Abstract: In a QAM microwave radio communications system an IF (intermediate frequency) input signal is amplified and predistorted, and the amplified IF signal is mixed with a local oscillator signal to produce an RF (radio frequency) signal which is amplified in a power amplifier for transmission, the predistortion compensating for non-linear gain of the power amplifier. Clipping in the power amplifier is controlled by down-converting part of the RF signal to produce an IF output signal, monitoring amplitude distortion of the RF signal by comparing the IF output signal with the IF input signal, and controlling the IF amplifier gain in dependence upon the monitored amplitude distortion.

Abstract: A frequency control system for a dual-mode radiotelephone (152-238; 252-320) operative to receive either an FM signal or a DQPSK signal. In a first embodiment, when operative to receive the FM signal, the frequency of the reference oscillator (192) of the radiotelephone (152-222) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (192) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (212). In a second embodiment, when operative to receive the FM signal, the frequency of an offset control oscillator (320) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (292) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (312).

Abstract: A radio device designed to receive a broadcast of player or performer conversations and/or sounds at sporting or performance events but to be useless after the event; and a method of picking up player or performance conversations and/or sounds and transmitting them to purchasers of the devices.

Abstract: Independent communication systems are provided with additional receivers that allow the systems to monitor one another's outbound control signalling channels. Secondary control signalling can be interleaved with the primary control signalling information on this communication resource, which secondary control signalling information is intended for reception and use by the monitoring system.

Abstract: An apparatus that includes various connectors, a battery compartment, and a circuit card is disclosed. The apparatus serves as a battery pack and programmer interface unit (BP/PIU) which mates with a cellular portable telephone (CPT) transceiver to form a CPT assembly. The CPT assembly is specifically adapted for use in connection with an automated registration and registration cancellation system, such as that utilized in the management of rental CPTs. The battery compartment is enlarged so that rental CPT assemblies may be used for a reasonable rental period without requiring a battery recharge. Electrical circuits protect various ones of signals provided at a communications port of the CPT transceiver. Connectors are arranged to permit a CPT programmer to read and program CPT parameters without disassembling the CPT assembly.

Abstract: Different commercial messages are broadcast to different demographically targeted audiences in a cable television system or the like. A first television channel contains television programs and periodic commercial messages. A second television channel contains alternate commercial messages. Demographic characteristics of a viewer are identified, and commercial messages are selectively provided from the first or second channel, depending upon the viewer's demographic characteristics. Demographic data can be input by a viewer via a remote control, downloaded to a subscriber's converter from a remote headend, or programmed into the converter at installation. Prioritization of the demographic characteristics of a plurality of television viewers watching a program together enables commercials to be targeted to the viewer having highest priority. Statistical data can be maintained concerning the number and identity of subscribers viewing specific commercials.

Abstract: A method of controlling a receiver's on-time (313). The radio receiver (109) receives radio frequency signals (309) of a predetermined duration (305) at an interval having a predetermined time period (301). The method varies the receiver's on-time (415, 417) until the data detector (205) is on the verge of failing to detect all of the data.

Abstract: A system for facilitating link continuity and prompt supervisory control in a communication system with discontinuous transmissions comprising varying the carrier power in a first communication unit and varying frequency deviation of a modulating signal to provide a continuous signal detectable by a second communication unit, where continuous monitoring at the second communication unit allows for rapid detection and reaction to received supervisory control signals through the use of continually comparing the received supervisory signal to an expected signal and qualifier signal to enhance the reaction time of the second communication unit.

Abstract: A self contained tilt rack video cassette library cabinet containing multiple VCP units with an XYZ motion tape cassette selection and delivery system to computer directed insertion in a subscriber VCP and return after play to a tilt rack library storage bin. The system includes activation means, movie selection means and a TV set at each subscriber location, an address mechanism in the system and a telephone line connection through a duplex modem to a computer having a monitor and keyboard with computer controlling XYZ carrier movement pick up of cartridges from and return to video cassette storage bins, insertion and extraction of selected video cassettes to and from subscriber dedicated video cassette players (VCP). Each VCP has an audio and video output connection to respective modulators each output connected to a combiner mixer.

Abstract: A remotely controllable message broadcast system includes a Central Programming Station, and many Remote Message Transmitters and repeaters. The Central Programming Station includes a library of broadcast messages and a set of Remote Message Transmitter programming instructions. A transmitter in the Central Programming Station transmits selected broadcast messages from the library and selected Remote Message Transmitter programming instructions from the set to all the Remote Message Transmitters over a wide area transmission network such as a licensed radio link. The transmitted instructions may include global instructions which apply to all Remote Message Transmitters and unique (addressable) programming commands which apply to an individual one of the Remote Message Transmitters. Each Remote Message Transmitter selectively stores received broadcast messages and programming instructions based on whether it is a global instruction or a unique addressable command for that particular Remote Message Transmitter.

Abstract: A two-way CATV network which in the preferred embodiment uses gating upstream narrowband filters in the distribution lines and/or trunks to substantially reduce upstream noise gathering. The filters sense the upstream signal energy and open in the event the energy exceeds a predetermined threshold.

Abstract: A compact multi-layer flat antenna structure incorporating a low noise block down-converter on the power divider network layer of the antenna. RF circuit losses are reduced, and the antenna/receiver combination is made more compact, for flush mounting. The antenna/receiver combination finds particular utility in direct broadcast satellite (DBS) applications for single or dual orthogonal polarizations. The connection between the antenna and receiver may be implemented in stripline/coplanar waveguide, or other known technologies such as microstrip, slotline, and finline.

Abstract: This invention relates to a satellite signalling system, such as a satellite paging system, having signal coverage over a very wide area. The satellite signalling system comprises a satellite to which is coupled an antenna for providing a signal beam having a variable beam area. The satellite can control the position of the antenna such that the signal beam can be directed in a predetermined sequence to a plurality of locations on earth. The antenna is arranged to vary the signal beam's area in dependence on the location to which the signal beam is directed. The signal beam comprises a data signal having a data rate which can be varied by the antenna in dependence on the beam area.