Nokia Corporation

Nokia Mobile Phones Limited

Seppo Rosnell

Jukka Varis

Tapani Ekman

Jukka Tapio Ranta

Mika Salmi

Simo Murtojärvi

Risto V&auml;is&auml;nen

Jouko H&auml;kk&auml;nen

A transmitter for generating modulated signals is shown, wherein in a first-type operating mode, a first digital signal is input into a digital-to-analog converter to obtain a first analog signal that is input into a first-type unit, in which a first-type modulated signal is generated in dependence on at least the first analog signal; and wherein in a second-type operating mode, a second digital signal is input into the digital-to-analog converter to obtain a second analog signal that is input into a second-type unit, in which a second-type modulated signal is generated in dependence on at least the second analog signal. Correspondingly, a wireless communication device is shown, as well as a base station, a module in a wireless communication device, a module in a base station, an integrated circuit, a method, a computer program and a computer program product.

Reuse of digital-to-analog converters in a multi-mode transmitter

The invention relates to a transmitter which comprises a modulator providing a phase-modulated constant-envelope radio-frequency signal, and to a method of controlling the power level of a signal output by such a transmitter. In order to enable a power control over a large power range, it is proposed that a provided phase-modulated constant-envelope radio-frequency signal is divided into two identical signals for the power control. A first control arrangement then controls the output power for higher power levels by controlling amplifications applied to the two signals. A second control arrangement controls the output power for lower power levels by controlling phase shifts applied to the two signals. The processed signals are then combined and provided as a power controlled output signal.

Power control for a transmitter

Switching mode power amplifiers using pulse width modulation (PWM) and pulse position modulation (PPM) for generating bandpass signals is disclosed. Fully digital implemented transmitter structures having QPSK inputs for phase and amplitude are described.

Switching mode power amplifier using PWM and PPM for bandpass signals

In a modulation system, in order to provide a two-level signal with a desired modulation which is suited to be amplified by a switching mode power amplifier, the modulation system may include a first constant envelope modulator modulating a signal according to a first control signal, a second constant envelope modulator modulating a signal according to a second control signal, and a combining portion combining the output signal of the first and said second constant envelope modulator to a single, two-level pulse-width-modulated signal. The information which is to be represented by the modulation of the single, two-level pulse-width-modulated signal is coded in the first and the second control signals. The invention relates equally to a corresponding method for generating a modulated signal.

Method and system for a generation of a two-level signal

The invention relates to a power control structure comprising a switching mode power amplifier for receiving an input signal, for amplifying the received input signal and for providing the amplified signal as output signal. In order to enable a power control over a large range while preserving the efficiency of the power amplifier, the structure further comprises a first control arrangement for controlling the power level of the output signal at least at higher desired power levels by adjusting a power supply provided to the switching mode power amplifier, and in addition a second control arrangement for controlling the power level of the output signal at least at lower desired power levels by adjusting the power of the input signal before it is provided to the switching mode power amplifier. The invention relates equally to a corresponding method.

Power control for a switching mode power amplifier

Phase modulating systems and methods for modulating the phase of a signal are based on a digital control signal used to select one of a plurality of carriers having different phase angles. In order to reduce the number of short delays that have to be applied to the original signal for obtaining the plurality of carriers, it is proposed that delay elements are arranged in a matrix form. Alternatively, phase shifts are realized by digital frequency dividers instead of by delay elements. Further alternatively or in addition, part of the required delay is approximated or realized by an analog phase shifter. In case the phase modulating system is to be employed for modulating signals of different frequencies, the digital control signal is scaled with a factor associated to the respective frequency in order to change the addressing range for selecting a carrier from among the plurality of carriers.

Phase modulating system

The invention relates to a system and a method for applying a continuously tuned phase shift to a periodic signal. In order to avoid distortions in the output phase shifted periodic signal, it is proposed that a phase shifting according to a first control signal and a phase shifting according to a second control signal are applied to the periodic signal in parallel. Both control signals are identical to each other, but shifted in time against each other. Both control signals are varying within a specific range and are jumping between their maximum and minimum value whenever a boarder of this range is reached. The first phase shifted periodic signal and the second phase shifted periodic signal are selected alternately in a way that phase shifts which are based on a portion of a control signal close to its jumping between its maximum and minimum values are excluded.

Application of a continuously tuned phase shift to a periodic signal

For establishing a local communication connection between a terminal ( ) of a cellular radio system and an accessory device ( ), a radio channel is identified ( ) on which there is no perceivable radio traffic in the cellular radio system, and a communication connection is established ( ) between the terminal and the accessory device on the identified radio channel. The radio channel is preferably a code channel of a CDMA system.

Accessory interface within a multiple channel radio apparatus

A linear power amplifier arrangement is used for providing a selectable amount of amplification to a radio frequency signal to be amplified. The arrangement comprises a first parallel amplifier branch and a second parallel amplifier branch and means for conducting the radio frequency signal to be amplified selectably to one of the parallel amplifier branches. Additionally it comprises in the first parallel amplifier branch a series connection of a predistorter and a nonlinear amplifier, where said predistorter is arranged to compensate for the nonlinearity of said nonlinear amplifier.

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Salo, Finland

Seppo Rosnell