Abstract: The preferred embodiment of the present invention encompasses an automatic frequency control system implemented in a radiotelephone (101). The radiotelephone (101) includes a frequency synthesizer. The frequency synthesizer uses a division ratio varied with time by a multi accumulator fractional N synthesizer (140) such that the effective division ratio may be varied by non-integer steps. The division ratio is programmed to realize the desired channel frequency, the desired modulation waveform, and any automatic frequency correction offset. An accurate clock is provided to the control logic (104) and the user interface (105) sections of the radiotelephone (101) using a second multiple accumulator fractional N division system (139). This second fractional N division system (139) is programmed based on the automatic frequency control programming of the first fractional N synthesizer (140).

Abstract: A method of invoking and canceling voice and data service between a mobile unit and a base station. Using a standard telephone system, the connection for a voice service and a data service is the same. With the introduction of the digital wireless link, the voice connection and the data connection are different. Therefore new dialing commands which indicate the intent of the connection are created. These commands can also be used to designate the intent of the call from a mobile unit capable of data and voice service but not capable of simultaneous voice and data service. They can also be used to invoke simultaneous voice and data services.

Abstract: A communication apparatus is small in power consumption and suitable for use in a portable radio communication apparatus. The communication apparatus includes a semiconductor power amplifier integrated circuit which uses a GaAs junction type FET having a gate bias terminal to which a gate bias voltage is applied. The integrated circuit decreases its amount of power consumption in a manner that the integrated circuit is operated to perform an amplification operation during a communication operation and not operated when a communication is interrupted or a time slot is not allotted to the communication apparatus itself. A detector detects a portion of a high-frequency signal to the amplifier circuit to provide an input to a gate bias generator which provides an input to an adder circuit, the output of which controls the bias on the power amplifier.

Abstract: A portable radio apparatus includes a housing, a receiver unit, a transmitter unit, and a hinge member. The housing has a longitudinally elongated, thin, rectangular parallelepiped shape. The receiver unit is arranged on one surface side of an upper portion of the housing to be located inside the housing. The transmitter unit is arranged on the same surface side of a lower portion of the housing as that of the receiver unit to be located outside the housing. The hinge member pivotally supports an upper end portion of the transmitter unit with respect to the housing. When the transmitter unit is pivoted through a predetermined angle, a lower end portion of the transmitter unit is unfolded to form a mount gap between the lower end portion and the housing.

Abstract: A method for the laying out of the infrastructure of a cellular communications network, notably with mobile units, the network being of the type constituted by a plurality of broadcasting transmitters, each broadcasting on its own broadcasting cell, at least certain of the cells being adjacent and having common overlapping zones, a system of management of the network assigning a single broadcasting cell to a given mobile unit at a given time, according to a given broadcasting transmitter assigning method, the method for the laying out consisting in determining the geographical location and the technical characteristics of each of the transmitters of the network in taking account of the conditions of entry/exit and of movement of the mobile units in the overlapping zones. Thus, the coverage of the network is determined dynamically, such as it is seen by the mobile units.

Abstract: A digital mobile radio receiver comprising a limiter amplifier, an orthogonal detector, a low pass filter, an A/D converter and a digital signal processing unit, additionally having a head amplifier able to vary a gain between said low pass filter and said A/D converter and a gain control unit controlling a gain of said head amplifier according to a command from said digital signal processing unit.

Abstract: A power boost system for a portable radiotelephone (10) employs a booster unit (52) to provide sufficient power for operation of the radiotelephone as a mobile unit in a cellular telephone system, and a junction box (54) which, in combination with a mechanical holder (56) allows for hands-free operation of the radiotelephone in the mobile telephone environment. The junction box is provided with a speaker (62) and a microphone (64) to facilitate the hands-free operation. The desired output power level for radiation from a vehicular antenna (72) is provided by a gain-controlled amplifier (80) in response to a pulse-width modulated command signal (48, 90) provided by a computer (12) within the radiotelephone. A memory (70) within the booster unit stores power level data for the higher levels of power to be used during transmission by the booster unit, the power level data being provided to the computer (12) in generating the power command signal.

Abstract: Determining transmit time of a received signal in a simulcast multi-site communication system begins when a communication unit transmits a message to one or more network receivers. Each receiver transports the received signal with a time stamp to each transceiver in the network via a digital communication network. Each transceiver calculates a wait period, during which, the transceiver may receive the signal and time stamp message from another receiver. Once the wait period expires, each transceiver, using a substantially similar selection method, selects the same received signal to broadcast. Each transceiver then determines a launch time for transmission of the selected received signal, wherein the launch time accommodates the worst case expected transport delay through the digital network.

Abstract: A selective call base station (100) for receiving a signal comprising a plurality of communication signals has an Analog-to-Digital (A/D) converter (220) for digitizing the signal. A memory (204) for storing the signal as a plurality of digitized bits (502-518), and a Digital Signal Processor (DSP) (218) for converting each of the plurality of digitized bits (502-518) into a frequency domain signal (FIG. 6) that has a plurality of frequency samples. The memory (204) stores the plurality of frequency samples corresponding to each of the plurality of digitized bits (502-518). A decoder (206, 218) decodes the plurality of communication signals from the plurality of frequency samples. The decoder (206, 218) further includes a generator (718) for generating a window (902) for measuring energy of at least one frequency sample of the plurality of digitized bits (502-518) in each of the plurality of communication signals.

Abstract: A mobile communications equipment which communicates with another equipment through a base station, and in which the state change of the mobile communications equipment based on the movement thereof, such as the movement from outside a service area into the service area, is detected and is notified to the user of the mobile communications equipment.

Abstract: Improved transmitter network with a single transmitter frequency.A transmitter network comprising a plurality of transmitters having a like transmitter frequency may cause disturbance to occur in an adjacent similar transmitter network. This disturbance is not of an echo signal type, so that cancellation thereof is difficult. For eliminating this disturbance as much as possible, a transmitter network is used wherein a main transmitter is associated with auxiliary transmitters having an aerial height which becomes smaller for auxiliary transmitters located more closely to the boundary of the desired coverage area of the system.

Abstract: In a communication system, a method that efficiently utilizes bandwidth of communication resources when transmitting first and second bandwidth messages to a communication unit may be accomplished in the following manner. When a central processor receives a message for the communication unit, it determines whether the message is of a first bandwidth message type or a second bandwidth message type. When the message is of the first bandwidth message type, the central processor transmits the message to the communication unit via a communication resource that is used primarily for transceiving first bandwidth type messages. When the message is of the second bandwidth message type, the central processor prepares a first bandwidth notification message and transmits it to the communication unit via the communication resource. The first bandwidth notification message informs a user of the communication unit that the central processor has the second bandwidth type message for it.

Abstract: A system for communicating data between an aircraft and ground unit over conventional amplitude modulated (AM) voice radio channels employs a data collection unit for collecting data desired to be transmitted, such as global positioning system (GPS) data, altitude, or aircraft identification information which is encoded by a data encoder. A gating means senses when the microphone of the AM transmitter is keyed, and passes the encoded data and the voice signals to the existing AM modulator of the AM voice transceiver. This results in a transmitted signal received by a receiving unit, such as a ground unit, which separates the received signal into an AM modulated voice signal and a AM data signal. The AM voice signal is demodulated by normal means into an audible signal, with the AM data signal being decoded by a data decoder into data.

Abstract: A method and apparatus system for cancelling a leak-through signal component generated by an interfering transmitter from a received/leak-through signal comprising a multiplier for multiplying the received/leak-through signal by a reference signal provided from the interfering transmitter. The system further includes an integrator for integrating the output of the multiplier to generate an estimate of the gain and phase of the leak-through signal component. A gain and phase adjustor, responsive to the generated gain and phase estimates, is also included for adjusting the gain and phase of the reference signal to generate a cancellation signal that is a substantially gain and phase matched estimate of the leak-through signal. The generated cancellation signal is then subtracted from the received/leak-through signal to substantially cancel the leak-through signal component.

Abstract: A direct conversion receiver, such as a paging receiver includes a local oscillator for mixing down to baseband a received radio frequency signal having a carrier frequency which is digitally modulated (FSK). To provide automatic frequency control, instead of using a control loop, the present invention includes means which at intervals evaluates the recovered digital signal to determine whether a predetermined quality thereof is within a selected D/A conversion range. A microcontroller including a D/A converter generates a control signal for the local oscillator to maintain the oscillator at a frequency such that the signal quality remains within the selected conversion range.

Abstract: In an arrangement for suppressing spurious signals occurring in a reception signal in a receiver of a high-frequency message transmission system, these spurious signals resulting from at least one neighboring channel that neighbors the useful signal channel, the reception signal is distributed onto at least two branches. One of the branches has a summing element as well as a circuit for generating a signal with a frequency, phase and amplitude corresponding to the useful signal. The other branch also has a summing element as well as a circuit for generating a signal having a frequency, phase and amplitude corresponding to the spurious signal. The signals of these branches are respectively supplied anti-phase to the summing element of the respective other branch.

Abstract: A portable radiotelephone (101) operating in a radio communication system (100), the portable radiotelephone including power consumption controller circuitry (200). The radiotelephone system (100) is designed such that the portable radiotelephone (101) needs to only intermittently receive paging information from a remote transceiver (103) during a control mode. The power consumption controller circuitry (200) utilizes a low cost, low power, low frequency oscillator (237) in conjunction with hardware and software for shutting down a portion of the radiotelephone (101) for a sleep period, when the radiotelephone (101) is not receiving information from the remote transceiver (103). The current sleep period is adapted depending upon the timing accuracy of the previous sleep period.

Abstract: An acoustic signal transmitting system comprises, at a transmission side, a plurality of acoustic input means each for producing an individual acoustic signal; a discriminating signal memory for storing a discriminating signal corresponding to each of the acoustic input means; a modulator for modulating the discriminating signal into a signal with a predetermined acoustic frequency; and a transmission controller for transmitting the acoustic signal when the acoustic input means output the acoustic signal and for transmitting the discriminating signal modulated by the modulator when the acoustic input means do not output the acoustic signal.

Abstract: In a system for reducing congestion of a radio paging channel, a radio base station has a radio paging channel for connection with a radio telephone. A first announcement section makes reception announcement for requesting a calling number and a called number to a calling subscriber in response to an incoming call for a call-back automatic announcement service from the calling subscriber. A registering section registers the calling and called numbers informed from the calling subscriber. A monitoring section monitors congestion of the radio paging channel of the radio base station, and outputs a detection signal when a usage of the radio paging channel becomes lower than a preset level. An outgoing call control section generates an outgoing call to a called subscriber in response to the detection signal from the monitoring section on the basis of the called number registered in the registering section.

Abstract: A mobile wireless communications system, comprises a plurality of base stations with associated respective coverage zones, each base station being connected to a central host computer and being capable of establishing two-way communication with mobile units in its associated coverage zone and a switch having a plurality of line interfaces connected to the base station. The host computer can select one of the base stations in range of an active mobile unit to establish a call therewith, determine the line interface associated with the call, determine when a hand off from one base station to the next is to occur as the active mobile unit moves between coverage zones, send a hand off message to the switch identifying the current active line interface and the target line interface after hand off associated with the call, and initiate a hand off by sending a call originate message to the next base station instructing it to originate the call on the target line interface.