Ericsson Gmbh

Texas Instruments Corporation

Telefonaktiebolaget Lm Ericsson (publ)

Jeffrey A Schlang

William O Camp, Jr

Charles Gore

Ronald D Boesch

Francesco Dantoni

Samuel D Pritchett

Aristotle Hadjichristos

Domenico Arpaia

Erik L Bengtsson

David R Pehlke

Scott R Justice

Alan R Holden

Sherif Embabi

Steven G Cairns

Charles Gore, Jr

Ron Boesch

Jacob Mannerstrale

M Ali Khatibzadeh

Baseband processor and communication overloading can be relieved in a portable wireless communication terminal by decentralizing power control () and frequency shift control () functions that are conventionally concentrated in the baseband processor. A timing sequencer () for power control can be integrated into a transceiver of the portable wireless communications terminal, thereby advantageously permitting power control signals to be generated on the transceiver side () rather than the baseband processor side. Shadow registers () containing information indicative of commonly used or repeated frequencies can be integrated into the transceiver side, thereby advantageously relieving the baseband processor of corresponding frequency shift control responsibilities. These responsibilities can be further relieved by integrating into the transceiver side a sequencer () cooperable with the shadow registers for controlling frequency shifting of a frequency generator on the transceiver side, and by integrating into the transceiver side further shadow registers () for programming the sequencer with desired frequency shift sequences.

Wireless communications with transceiver-integrated frequency shift control and power control

An RF receiver apparatus () is provided physically separately from a cooperating baseband processor apparatus (). The RF receiver includes a mixer circuit () and an analog IF-to-digital baseband converter () formed on an integrated circuit. Sampling frequencies of the analog IF-to-digital baseband converter are controlled by the RF receiver apparatus.

If-to-baseband conversion for flexible frequency planning capability

A digital signal processor generates in-phase, quadrature-phase and amplitude signals from a baseband signal. A modulator modulates the in-phase and quadrature-phase signals to produce a modulated signal. A phase locked loop is responsive to the modulated signal. The phase locked loop includes a controlled oscillator having a controlled oscillator input. An amplifier includes a signal input, amplitude control input and an output. The signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal. The in-phase and quadrature-phase signals may be normalized in-phase and quadrature-phase signals. Alternatively, a phase tracking subsystem may be provided that is responsive to the quadrature modulator to produce a phase signal that is responsive to phase changes in the modulated signal and that is independent of amplitude changes in the modulated signal. An amplitude tracking subsystem also may be provided that is responsive to the modulator to produce an amplitude system that is responsive to amplitude changes in the modulated signal and that is independent of the phase changes in the modulated signal. An amplifier has a signal output, an amplitude control input and an output. The signal input is responsive to the phase signal and the amplitude control input is responsive to the amplitude signal.

IQ modulation systems and methods that use separate phase and amplitude signal paths

An RF amplifier for a transmitter develops a phase modulation command representing a desired phase modulation of an RF signal, and an amplitude modulation command representing a desired amplitude modulation of the RF signal. An oscillator develops an RF input signal phase modulated based on the phase modulation command. A power amplifier receives the RF input signal and amplifies the RF input signal based on the amplitude modulation command to develop an RF output signal. A modulation control is operatively associated with the oscillator. The modulation control includes a phase memory for storing phase correction information correlating the amplitude modulation commands to a phase modulation error and a phase control for varying the phase modulation command based on the phase modulation error to correct for unintended phase errors created by amplitude modulation of the power amplifier.

Amplitude modulation to phase modulation cancellation method in an RF amplifier

An RF amplifier includes a phase modulator developing a phase modulated RF input signal to be transmitted. A power amplifier receives the RF input signal and amplifies the RF input signal to develop an RF output signal. An amplifier control is operatively associated with the phase modulator and the power amplifier. The amplifier control includes a memory for storing correction information correlating desired amplitude of the RF output signal relative to actual amplifier amplitude, and a control varies power amplifier supply voltage responsive to the correction information to linearize amplitude modulation in the power amplifier.

Circuit and method for I/Q modulation with independent, high efficiency amplitude modulation

An RF amplifier includes an oscillator developing an RF input signal to be transmitted. A power amplifier receives the RF input signal and amplifies the RF input signal to develop an RF output signal. An amplifier control is operatively associated with the oscillator and the power amplifier. The amplifier control includes means for developing a control signal representing a desired amplitude of the RF output signal. A memory stores correction information correlating actual amplitude of the RF output signal relative to the control signal, and a control varies the power amplifier circuit supply voltage using the control signal modified responsive to the correction information for the desired amplitude.

Circuit and method for linearizing amplitude modulation in a power amplifier

A dual band mobile station including a main channel synthesizer and an offset synthesizer for generating the transmit frequency and the receive intermediate frequency (IF) required for operation in each of two different bands characterized by different transmit-receive channel offsets. According to the present invention, the main channel synthesizer does not have to change its frequency when the mobile station switches between transmission and reception in either of the two bands so long as a common IF is selected for both bands, which is equal to one or the other of the channel offsets. This IF selection also allows for a reduction in the tuning range of the main channel synthesizer.

Dual band mobile station

According to a second embodiment of the invention, a mobile phone receiver comprises a first down converter using a first local oscillator frequency which can be tuned in frequency steps by a programmable digital frequency synthesizer PLL which is locked to a reference frequency. The first down converter converts received signals to a first IF for filtering. A second down converter using a second local oscillator converts first IF signals to a second IF. The second local oscillator frequency is generated using a second digital frequency synthesizer PLL which locks the second oscillator to the reference frequency. A third down converter mixes the transmit frequency with the first local oscillator frequency to produce a lock frequency. A third digital frequency synthesizer PLL compares the lock frequency and the reference frequency to control generation of the transmit frequency.

Growing community of inventors

Dallas, TX, United States of America

Jeffrey A Schlang