Abstract: A satellite-based communications system operating at high data rates includes a plurality of satellites each having uplink and downlink antennas for transmitting and receiving a plurality of signals utilizing a plurality of spot beams to and from a plurality of coverage areas at a predetermined range of frequencies. The system also includes a plurality of user terminals for transmitting and receiving signals to and from the plurality of communications satellites at the predetermined range of frequencies and at one of the first plurality of data rates. Each of the user terminals having a steerable antenna for tracking relative movement of each of the user terminals with respect to each of the plurality of communications satellites and for tracking movement of each of the plurality of communications satellites in order to maintain communications with the plurality of communications satellites.

Abstract: A combination phone and modem interfacing a computer with switching means using a common transmitter/receiver for communicating wirelessly with a base transmitter/receiver. Controls on the keypad of the phone permit the user to conveniently select by depressing the appropriate key for transmitting or receiving voice messages for the phone or digital data for the computer. In one configuration, the phone, transmitter and receiver are in an enclosure separate from the computer and modem. In another configuration, the phone, transmitter, receiver and modem are in an enclosure separate from the computer.

Abstract: In a radio receiver, a voltage-controlled crystal oscillator of a radio frequency section produces a local carrier for mixing it with a received radio signal to produce an analog output signal. A threshold decision circuit comprising an average circuit and a comparator compares this output signal with a decision threshold and produces a digital signal. A synchronization detector produces an in-sync signal when a synchronization bit pattern is present in the digital signal. Otherwise, it produces an out-of-sync signal. The radio-frequency section is periodically activated and deactivated by power saving pulses. Frequency control circuitry varies a control voltage applied to the voltage-controlled crystal oscillator by a predetermined amount if a predetermined number of the power saving pulses is produced after the instant the out-of-sync signal is produced.

Abstract: A converter, transmitter and/or receiver for mixing an input signal (I.sub.RF) having a first frequency (RF) with an input signal (I.sub.LO) coming from a local oscillator having a second frequency (LO), and for producing an output signal (O.sub.IF) having an intermediate frequency (IF), with rejection of the harmonics of the second frequency (LO) up to a very high order, for example, higher than the tenth order. The device includes a double balanced ring mixer (17) of field effect transistors (12, 13, 14, 15), having a first and a second pair of input terminals (3, 4; 1, 2) and having a pair of output terminals (5, 6), and a first and a second coupler (18, 19) respectively acting as a phase separator and phase combiner for the input signal (I.sub.RF) having the first frequency (RF) and output signal (O.sub.

Abstract: A modular broadband transmission system and method include an input signal connector that receives an input signal which is then divided into N parts and amplified with an amplifier have N power amplifier modules. Outputs of the N power amplifier modules are passed through transmission lines and to a radial combiner that combines the outputs. The radial combiner, transmission lines and power amplifier modules are configured such that if one of the power amplifier modules fails, the other power amplifier modules may still operate acceptable well, with minimal impact on total output power. An output of the amplifier is provided to a coupler that measures a power level of the output signal and feeds the measured power level back to a controller where the controller adjust an overall output power based on the number of the power amplifier modules that are functioning properly.

Abstract: Dual antenna radiotelephones which include antenna-management switching means that allow the radiotelephones to assume a plurality of different static and dynamic configurations, either adaptively or in response to user commands. These switching means may also provide a means for connecting the radiotelephone to one or more external antennas, and may facilitate use of diversity reception and or transmission techniques. In one embodiment of the present invention, the radiotelephone includes a transmitter, first and second receivers, a user interface, first and second antennas, and antenna switching means. These antenna switching means selectively couple the transmitter, the first receiver and the second receiver to the first and second antennas.

Abstract: The invention relates to a radio receiver comprising a control circuit (7) for supplying coded messages derived from a radio signal to at least one memory arrangement (12, 28), for receiving control data derived from the coded messages which control data originate from at least one memory arrangement (12, 28), and for forming the messages from the control data in a form suitable for a visual display (13) and/or a voice output circuit (14). For providing a more flexible radio receiver, a reading device (16) for reading data of an external first memory arrangement (28), and a second memory arrangement (12) are coupled to the control circuit (7). The first memory arrangement (28) is used for storing control data for region-specific road or area categories and the second memory arrangement (12) is used for storing control data for supra-regional road or area categories which have each a respective class name.

Abstract: A mobile communication system includes mobile terminals, radio base stations belonging to low- and high-speed mobile communication systems, and a mobile subscriber connecting apparatus to which the radio base stations are connected. The system uses both a first communication mode including the low-speed mobile communication system and a micro-cell zone and a second communication mode including the high-speed mobile communication system and a macro-cell zone.

Abstract: A mobile radio station is disclosed having a device for synchronization with data streams transmitted over radio channels by base stations of a cellular mobile radio network. After an erroneous attempt at synchronization with a radio channel that has a receiving level, another attempt at synchronization with the radio channel is made after a delay. The delay depends on the receiving levels of different radio channels, the number of erroneous synchronization attempts, the number of radio channels with which the mobile radio station has already been synchronized, or the velocity of the mobile radio station. A new delay may also be obtained based on the old delay and the last two receiving levels.

Abstract: A method for controlling a transmitting power of a mobile station radio communicating with a base station is disclosed including the step of: adjusting the transmitting power of the mobile station by use of an average value of a power strength received over a predetermined period during communication, a transmitting power of the base station analyzed from a packet which is transmitted from the base station, and a transmitting power determined by a desired receiving power of the base station.

Abstract: Each cell area within a mobile telecommunications service area is categorized in accordance with its associated terrestrial conditions and irregularities. As an illustration, each cell area is categorized as either a urban, suburban or rural area. Data indicative of the assigned category are then broadcast over a control channel to all mobile stations currently traveling within the respective cell area. The mobile stations then utilize the received data to determine appropriate air-interface settings and parameters and effectuate location adaptive air-interfaces with a serving mobile telecommunications network.

Abstract: A radio pager of the present invention includes battery terminals each having an inductance component. The pager therefore reduces the fall of antenna efficiency as far as possible without resorting to any extra part. In addition, a coin type battery is located in the vicinity of short bars included in the pager so as to prevent the antenna efficiency from decreasing.

Abstract: The invention relates to a method for generating frequencies in a direct conversion transceiver of a radio communication system operating in two different frequency bands. In this method a first frequency band comprises a first transmission frequency band and a first reception frequency band, and a second frequency band comprises a second transmission frequency band and a second reception frequency band. The frequencies are Generated by using one frequency synthesizer (12) and a reference oscillator (14), which generates an essentially constant mixing frequency (L04).