Abstract: The method and apparatus of the present invention improve the immunity to interference of a radio receiver. The power level of a received signal is detected. If the power level meets or exceeds a predetermined power threshold, the low noise amplifier is by-passed, thus increasing the intercept point of the receiver components.Alternative embodiments include the use of an RF power detector to control the front-end gain as a function of jammer power. In lieu of a switchable RF gain block, several methods of continuous gain control are proposed. Continuous gain control allows the interference suppression and sensitivity of the receiver to be adjusted at lower signal levels than the switchable gain block.

Abstract: An EMI shielding apparatus has an outer peripheral wall extending around a combined area of predetermined shape and dimensions for enclosing at least two adjacent areas on a printed wiring board to be shielded from one another. A single transverse wall extends between opposing portions of the peripheral wall to divide the combined area into the two adjacent sub-areas to be shielded from one another. The single transverse wall is of single wall thickness, reducing the EMI shield footprint. The peripheral wall and transverse wall may be formed integrally as one frame, or from two or more adjacent sub-frames.

Abstract: A data communication system which enables an electronic accessory, such as a computer, to communicate data in both an analog type radiotelephone system and a digital type radiotelephone system. The data communication system first determines in which type of system it is operating and the dual mode radiotelephone (101) then uses the data signal at either the analog input port (104) or the digital input port (105), depending on the type of system.

Abstract: A concentrated subscriber wireless remote telemetry system which uses low-cost remote communication devices operating on existing wireless communication systems in order to provide real-time reading and control of remote devices. The metering system comprises at least one powerline remote metering device which collects and forwards telemetry data to an associated wireless remote telemetry device. The wireless remote telemetry device relays the telemetry data to a central controller over existing wireless communication systems, such as cellular base stations, using existing communication standards. The wireless remote metering device transmits various messages over a shared random access channel to the central controller. The central controller transmits messages to the wireless remote metering unit over a paging channel. The wireless remote metering unit may operate in a half-duplex mode only.

Abstract: A keypad is operated by the user to generate keypad data indicative of a destination telephone number. A storage area stores data related to the calling plan and containing data indicative of call restrictions that may apply to the destination telephone number. A call restriction storage area is used to store user-selectable call restriction data. A processor accepts and uses keypad data to access the data storage area. The processor compares data indicative of call restrictions that may apply to the destination telephone number with the user-selectable call restriction data to determine if any user-selectable call restrictions apply to the destination telephone number. The processor sets an enable signal to an enabled state if no call restrictions apply to the destination telephone number and sets the enable signal to a disabled state if call restrictions do apply to the destination telephone number.

Abstract: A multi-stage low power, high dynamic range variable gain amplifier comprises an input stage cascaded with one or more current amplifier stages, whereby the gain of each stage may be independently controlled. The input stage may be comprised of a variable transconductance amplifier using variable emitter degeneration. The current amplifier may be comprised of a differential Darlington amplifier coupled to a differential cascode amplifier. The transconductance amplifier converts an input voltage signal to a current signal. The variable gain amplifier is designed for efficient low power operation.

Abstract: An amplifier circuit for providing an amplified signal in response to an input signal. The amplifier circuit includes an input network for applying the input signal to a selected at least one of a plurality of amplifier stages. An output network is provided for coupling the amplified signal from the selected at least one amplifier stage. The appropriate amplifier stage is selected by a control circuit in response to a desired power value of the amplified signal. By selectively activating only the amplifier stage(s) that are necessary to provide the desired level of output power, increased DC efficiency can be accomplished in applications that require an amplifier which operates linearly over a wide dynamic range.

Abstract: First and second data sources transmit a data signal on a data connection and a transmit clock signal on a clock connection. The data signal is clocked into a FIFO resident in the network interface equipment in response to the transmit clock signal, and out of the FIFO to the network in response to a reference clock signal. The FIFO generates a signal indicating how full it is and a local clock generator which generates the transmit clock signal in response to this status indication signal. The first and second data sources hold the data signal and transmit clock signal high for longer than a single period of the reference clock signal when switching between them. The local clock generator alters an average rate of the transmit clock signal in response to the status indication signal from the FIFO in order to keep it half-full.

Abstract: An antenna system for a communication device. A whip antenna is surrounded by a helical antenna. A switch couples the helical antenna to the signal source when the whip antenna is in a retracted position. The whip antenna is comprised of an upper conductive portion, a lower conductive portion, and a dielectric portion which isolates the upper and lower conductive portions from each other. A conductive sleeve member surrounds the whip antenna and is slidably mounted thereon. In a first embodiment, when the whip antenna is extended, the conductive sleeve member slides over the dielectric portion, coupling the upper and lower conductive portions together. As the whip antenna is retracted, the helical antenna pushes the conductive sleeve member to the top end of the whip antenna, isolating the whip antenna from the helical antenna. In a second embodiment, the helical antenna is an integral part of the conductive sleeve member.

Abstract: A method and apparatus for negotiating service configuration in a digital communication system is disclosed. In an exemplary embodiment the service negotiation system is implemented in a wireless spread spectrum communication system. The service configuration comprises data rates, frame formats and types of services. Types of service may include speech encoding, facsimile or digital data services. Further described herein is a digital transmitter and receiver using the service negotiation system to provide service configuration mutually acceptable at both ends of a communication link.

Abstract: A system and method for processing wideband data within digital FM transceiver. A digital FM demodulator within the transceiver produces a demodulated information signal in response to the FM signal. The digital FM receiver also includes a wideband message processing section for recovering message information from the demodulated information signal. A word register circuit within the wideband message processing section stores one or more repetitions of a message word recovered from the demodulated information signal. During operation of the FM receiver in a control channel mode, a dotting detector within the wideband processing section is used for detecting a first dotting sequence within the demodulated information signal. Similarly, the dotting detector serves to detect a second dotting sequence within the demodulated information signal during operation in a voice channel mode.

Abstract: A novel and improved antenna coupler useful in an adapter for a portable radiotelephone. In a first embodiment, a plurality of curved bands of metal are positioned on a ground plane, with at least one of the plurality of curved bands of metal being electrically isolated from the ground plane so as to couple RF signals to and from the antenna of a portable telephone. At least one ground pin is also mounted on the ground plane. When a portable radiotelephone is interfaced with the antenna coupler, the at least one ground pin makes electrical contact with assembly screws or an external ground pad of a battery charging port on the portable radiotelephone. In a second embodiment, a coupling pin makes direct contact with an component of the RF chain of the portable radiotelephone. In a third embodiment, a helical coupler surrounds the antenna of the portable radiotelephone.

Abstract: A filter comprising a plurality resonator stages between sequentially coupled between input and output ports. The resonator stages are arranged such that at least one non-sequential pair of stages are physically adjacent. The non-sequential pair of resonator stages are separated by a common internal wall, which defines a bypass coupling aperture therebetween. During operation of the filter, attenuation poles are formed in the filter response due to bypass coupling between the non-sequential pair of resonator stages through the bypass coupling aperture. The preferred U-shaped arrangement of the resonator stages enables the formation of attenuation poles, without using an external bypass connection, by permitting inductive or capacitive bypass coupling through the bypass aperture.

Abstract: The process of the present invention enables a mobile radiotelephone to operate at a 100% duty cycle while providing closed loop power control. The base station measures the signal to noise ratio of the signal from the mobile and compares that SNR with the SNR threshold values the base station has for each data rate the mobile is capable of transmitting. The base station then generates power control commands to instruct the mobile to change its power depending on the outcome of the comparisons.

Abstract: A novel and improved dual band antenna system comprising an inner antenna element surrounded by an outer antenna element. In a first embodiment, the inner antenna element radiates and receives RF signals in a first RF band, and the outer antenna element radiates and receives RF signals in a second RF band. Optionally, the inner and outer antennas may be coupled together when operating in the first RF band in order to improve the antenna gain pattern of the dual band antenna. In a second embodiment, the inner antenna element radiates and receives RF signals in both the first and second RF bands. In this second embodiment, when operating in the second RF band, the outer antenna element is grounded, thus altering the signal length of the inner antenna element to resonate in the second RF band.

Abstract: A novel and improved method of acquisition in a spread spectrum communication system is presented. In the present invention, a large window of PN chip offset hypotheses are searched and if an energy signal is found that might indicate the presence of the pilot signal having one of the chip offsets of the large search window, then a search of a subset of offset hypotheses, or small window, is searched.

Abstract: A bus interface unit disposed for incorporation within a microprocessor system having a local microprocessor bus, a memory unit, and a system bus coupled to the memory unit is disclosed herein. The bus interface unit includes a bus control unit having an address latch for latching N-bit memory addresses impressed upon the local microprocessor bus by the microprocessor. Each of the N-bit memory addresses identifies one or more M-bit memory locations within the memory unit. The bus interface unit further includes a multiplexing interface for transferring data associated with the M-bit memory locations between the system bus and the local microprocessor bus during microprocessor memory access cycles. A programmable wait state generator serves to control the duration of the microprocessor memory access cycles in order to accommodate address and data transfer between the system bus and the local microprocessor bus during both memory read and write access cycles.

Abstract: A system and method for estimating the quality and path loss associated with a communications channel on the basis of the power of a pilot signal received by a communications receiver. The communications receiver measures a received signal power, and also makes a relative pilot strength measurement of a received pilot signal. The power of the pilot signal is then computed using the received signal power and the relative pilot strength measurement. An indication of channel quality based on the pilot signal power may be provided to a user of the communications receiver. Path loss of a communication channel between a base station and a remote site station is also estimated. The base station also transmits an indication of the power at which the pilot signal was transmitted. An estimate of the path loss is then made by determining the difference between the indicated power of the transmitted pilot signal and the received pilot signal power.