Nokia Mobile Phones Limited

Nokia Corporation

Nokia Technologies Oy

Mokia Mobile Phones Ltd.

Heikki Mattila

Jorma Matero

Marko E Leinonen

Jaakko A Hulkko

Juha Johannes Salokannel

Niko Kiukkonen

Jari Henrik Junell

Antti Olavi Kangas

Harri Lilja

Mikko Veijo Halttunen

Seppo Kangasmaa

Hannu Pakonen

Kjell I Ostman

Pertti Kangas

Jukka Kansanaho

Simo Kaleva

Tapio Rautava

Erkki Tiittanen

A method for operating a receiver and a device are provided. The device comprises a first and a second antenna, a receiver operationally coupled to the first antenna and a transceiver operationally coupled to the second antenna. The receiver receives information in bursts on a first band of radio frequencies. A controller of the device measures signal strength of the information received with the receiver, compares the measured signal strength to a reference value and enables operation of the transceiver if the measured signal strength is above the reference value, and limits operation of the transceiver during reception of the bursts if the measured signal strength is below the reference value.

Operating multi-service receiver in non-interfering manner

A system for allocating communication resources in an apparatus. For example, an apparatus that is enabled to support a plurality of wireless transports may identify a resource-intensive task to be executed using a wireless transport. Prior to the execution of the resource-intensive task, the apparatus may determine if any wireless links already exist, and whether to alter operational parameters for one or more of the existing wireless links in order to make resources available for expediting completion of the resource-intensive task.

Channel management via link parameter adjustment

A transmitter has an input for receiving a signal, gain controller for applying a first gain to the received signal, a first path for providing a second, relatively high gain for the received signal, a second path for providing a third, relatively low gain for said received signal, a transmitter for transmitting a signal and a controller to cause a received signal to pass through the gain controller and the first path when a relatively high gain is to be applied to the received signal and to cause a received signal to pass through the gain controller and the second path when a relatively low gain is to be applied to the received signal. When a change is made from using one of the first and second paths to using the other, the power of the signal transmitted by the transmitter varies by less than or equal to a predetermined amount.

Transmitter

A dual-mode radiotelephone terminal includes a .pi./4-shift DQPSK modulator (11). A dual-mode modulation is achieved by mixing an output of a transmitter oscillator (16) with an output of an offset oscillator (18) to form an injection signal (LO) at a final transmitter frequency, the injection signal being further modulated with a quadrature modulator in a digital mode of operation. In an analog mode of operation the transmitter oscillator or the offset oscillator is frequency modulated and the quadrature modulator is disabled with a bias signal, thereby passing the frequency modulated injection signal without substantial attenuation. The LO signal is regenerated and also phase shifted with a circuit (35) having a frequency multiplier (30) and a frequency divider (34). The circuit outputs two local oscillator (LO) signals (LOA and LOB), each of which directly drives an associated quadrature mixer (36, 38) of the modulator. A control signal is employed for selectively enabling and disabling various of these components as a function of the operating mode, thereby conserving power.

Dual mode FM and DQPSK modulator

A dual mode transmitter with bias control is described wherein an RF signal from a system modulator is fed to a gain control circuit, which can be either a voltage controlled amplifier or attenuator. The ultimate transmitter output power level depends on the attenuation/gain of the gain control circuit. The output signal from the gain control circuit is fed to a driver amplifier which amplifies the signal and feeds it to a power amplifier circuit, which may be comprised of several stages of bipolar transistors or GaAs FETs. The modulated signal to be transmitted is then fed from the power amplifier circuit through a coupler to an antenna terminal. The coupler is connected to an RF detector and is used for RF level monitoring. The Rf level signal from the RF detector is applied to a comparator circuit. An improved combination is provided by incorporating a bias control circuit. A Vpwr signal is applied as one input to the bias control circuit and a mode signal is applied as the other input. When the mode signal is 'on' or present it signifies that the digital transmission mode is to be employed. When the mode signal is ' off' or at zero level, it indicates that the analog transmission mode is to be employed. The bias control circuit provides three bias signal outputs, V.sub.b1 applied to the driver amplifier, and V.sub.b2 and V.sub.b3, applied to the power amplifier. The levels of V.sub.b1, V.sub.b2 and V.sub.b3 are varied for the analog and digital transmission modes.

Dual mode amplifier with bias control

A dual-mode radiotelephone terminal includes a .pi./4-shift DQPSK modulator (11). A dual-mode modulation is achieved by mixing an output of a transmitter oscillator (16) with an output of an offset oscillator (18) to form an injection signal (LO) at a final transmitter frequency, the injection signal being further modulated with a quadrature modulator in a digital mode of operation. In an analog mode of operation the transmitter oscillator or the offset oscillator is frequency modulated and the quadrature modulator is disabled, thereby passing the frequency modulated injection signal without substantial attenuation. The LO signal is regenerated and also phase shifted with a circuit (35) having a frequency multiplier (30) and a frequency divider (34). The circuit outputs two local oscillator (LO) signals (LOA and LOB), each of which directly drives an associated quadrature mixer (36, 38) of the modulator. In another embodiment the dual-mode radiotelephone terminal includes a VHF synthesizer (23), a UHF synthesizer (21), and a local oscillator (4C) that provides a signal only when operating in the analog receiving mode. The local oscillator signal is mixed with a first IF signal for providing a second IF signal when operating in the analog receiving mode or in a standby mode. A control signal is employed for selectively enabling and disabling various of these components as a function of the operating mode, thereby conserving power.

Dual mode radiotelephone terminal selectively operable for frequency

Structure and technique, for calibrating a vector modulator that does not require a network analyzer, are disclosed which are incorporated in a vector modulation system comprising a standard vector modulator circuit including means for shifting phase to adjust the relative phases of the I and Q components of the modulated RF carrier. Means for attenuating are included in the I and Q modulation system to adjust the relative amplitude of the modulation signals. The disclosure describes a technique wherein the microwave transmitter's I and Q phase difference is measured by measuring the power levels of the I and the Q signals. The power levels are compared and a correction value is stored in a read-only memory to compensate for the error. More particularly, the error compensation is achieved by first determining amplitude error or unbalance by I and Q signal power measurement and an amplitude compensation signal is stored, then a power measurement is carried out for phase compensation and a phase compensation signal is stored.

Tuning techniques for I/Q channel signals in microwave digital

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Oulu, Finland

Heikki Mattila