Abstract: A mobile communication device with a display may be configured to apply pulse width modulation (PWM) signals to light emitting diodes (LEDs) for providing backlighting for the display, monitor ambient light conditions during off periods of PWM signals applied to the LEDs and adjust the PWM signals based the monitored ambient light conditions.

Abstract: A mobile communication device with a display may be configured to apply pulse width modulation (PWM) signals to light emitting diodes (LEDs) for providing backlighting for the display, monitor ambient light conditions during off periods of PWM signals applied to the LEDs and adjust the PWM signals based the monitored ambient light conditions.

Abstract: The present invention relates to a radio communication unit (20) comprising radio communication means (23, 25, 27) for communication (reception and/or transmission) in one or more frequency ranges with associated channel spacings. The radio communication means use oscillator signals for channel selection in the frequency ranges. The radio communication unit further comprises a system clock (77) generating a clock signal having a predetermined frequency that is not divisible by all the channel spacings. According to the invention the oscillator signals used in the channel selection are generated by a frequency synthesizer circuit (29) in the form of a fractional-N PLL circuit, said clock signal being fed as a reference frequency signal to the fractional-N PLL circuit. The invention also comprises a radio telephone comprising such a radio communication unit and the use of such a radio communication unit.

Abstract: The invention relates to: An electronic circuit for controlling the output frequency from a frequency synthesizer, said output frequency being based on a reference frequency from a voltage controlled crystal oscillator (VCXO), the latter being regulated by a D/A converter controlled by a processing circuit that monitors a frequency error. The invention further relates to a method and a computer program, a computer readable medium and a dual mode mobile telephone. The object of the present invention is to provide a simple and economic scheme for overcoming the temperature limitations of a VCXO based frequency synthesizer.

Abstract: A method and arrangement enabling a mobile station (MS1), operating in standby mode and monitoring a control channel (CC1) in a first radio communication network (NET1), to scan for other radio channels (CC4-CC6) without missing messages, e.g. page messages, on the control channel (CC1) intended for the mobile station (MS1). Each message comprises at least one repeated block of information bits. Upon receipt of a message on the monitored control channel (CC1), the mobile station (MS1) dynamically determines a time period during which the blocks of information conveying the message contains no new information intended for the mobile station (MS1). At least part of said time period is then used for scanning of other radio channels (CC4-CC6).

Abstract: A signal combining device and method allows a mobile unit to use a single antenna to receive and transmit information in two or more frequency ranges. The combining device includes a first and second transmitting circuits and a first and second receiving circuits, which are connected to a matching device. The matching device, in turn, is connected to the antenna. The first transmitting circuit and the first receiving circuit are designed to transmit and receive, respectively, a digital signal, and the second transmitting circuit and the second receiving circuit are designed to transmit and receive, respectively, an analogue or a digital signal. By using the signal combining device it is possible to combine signals of different frequency bands, especially digital signals and analogue signals of different frequency bands. As such, the present invention allows for the use of a common antenna in a dual mode radio.

Abstract: The present invention is related to a method and arrangement in a mobile station operating in standby mode and monitoring a first control channel in a first radio communication network. The transmission of messages (703-708) on the first control channel occurs in periodic occuring frames (700). Each frame (700) comprises a first sequence of messages (701), in which no message is addressed to a specific mobile station, and a second sequence of messages (702) that may comprise messages addressed to specific mobile stations. The mobile station determines for at least a first frame (700) a time period during which no part of a message, belonging to the second sequence of messages (702), will be transmitted. Said time period is used by the mobile station to perform actions other than receiving radio signals carrying the first control channel, e.g. entering sleep mode or scanning for control channels in a second radio communication network.

Abstract: A multiple-mode receiver incorporating direct conversion (processing received signals using intermediate frequencies within the same frequency range as the received signal bandwidth) rather than superheterodyne circuitry, allowing receiver hardware components to be re-used rather than replicated for each band. Various embodiments are disclosed in which low pass filters, mixers, quadrature generators, oscillators, and amplifiers are re-used.