70results about "Angle to amplitude modulation conversion" patented technology

In an adaptive modulation and coding method one or more adjustable values are created (S1), each corresponding to at least one of a plurality of available modulation and coding levels applicable to a signal transmitted from a transmitter to a receiver, and each representing a change to the level(s) to which it corresponds. One or more of said adjustable values is / are adjusted in dependence upon whether or not the signal is received successfully by the receiver (S2-S5). One of said available modulation and coding levels is selected (S6-S8) to apply to the signal based on such an adjustable value. Such a method can enable the appropriate modulation and coding level to be selected even when the path and channel conditions vary. The method is applicable to selecting modulation and coding levels in a high-speed downlink packet access system of a wireless communication network.

A modulator arrangement includes a power amplifier which receives a carrier signal and has a current control input and a voltage supply input. The modulator arrangement further includes a supply voltage modulator having an output coupled to the voltage supply input and an input coupled to the data input and a bias current modulator with an output coupled to the current control input and an input coupled to the data input. A control unit is provided which has a power control output coupled to the supply voltage modulator and to the bias current modulator to control the supply voltage modulator and the bias current modulator depending on a power control signal.

The pulse modulated RF power control method includes an output amplitude control step for controlling amplitude of a pulse output, and a duty control step for controlling a duty ratio of the pulse output. The output amplitude control step performs a constant amplitude control to control an amplitude value of the pulse output so that the amplitude value becomes equal to a set amplitude value. The constant amplitude control according to the output amplitude control, for instance, gives a feedback of the amplitude value of the pulse output outputted by the power control, obtains a difference value between the feedback value and the set amplitude value, and controls the amplitude value of the pulse output so that the difference value becomes zero.

Embodiments of the invention may provide for a digital LINC (linear amplification with nonlinear components) transmitter. The digital LINC transmitter may include a signal component separator, at least one digital delay modulator, a frequency synthesizer, at least one power amplifier, a power combiner, an antenna, and a mismatch compensator. Additionally, systems and methods may be provided for compensating for phase and amplitude mismatches between two signal paths.

Provided is a transmission modulation apparatus, using polar modulation of two-point modulation scheme, capable of completing a timing adjustment of a BB phase modulation signal and BB amplitude modulation signal in a short time. A phase modulation section (10) that performs two-point modulation with a PLL circuit is provided with a switch (17) to make the PLL circuit open loop, and when a first delay section (5) corrects the deviation in synchronization between the BB phase modulation signal and BB amplitude modulation signal, the switch (17) is turned off to make the PLL circuit open loop.

Transmission apparatus capable of reducing distortion of the vector modulation wave that is the transmission output to a sufficiently small level is provided. An amplifying section (105) generates a vector modulation wave based on an amplitude component modulation signal and a phase modulation wave. A synchronous demodulating section (107) detects the vector modulation wave, generates a synchronous demodulation signal, and sends this to a band filtering section (108). The band filtering section (108) extracts a signal of the frequency component of the distortion from a synchronous demodulation signal outputted by the synchronous demodulating section (107). A controlling section (109) then refers to the distortion component signal extracted by the band filtering section (108), controls a delay time adjusting section (103) in such a manner that the signal level of the distortion component becomes small, adjusts a delay time difference between the amplitude component modulation signal and the phase component modulation signal, and reduces distortion of the modulation wave.

Polar modulators include a phase splitter, a controller, variable current sources, transistor circuits, and a combiner. The phase splitter splits a RF carrier signal into quadrature component signals that are 90 degrees out of phase with each other. The controller generates modulation control signals based on information that is to be transmitted. The variable current sources each generate a variable amplitude current signal based on a different one of the modulation control signals. Each of the transistor circuits amplify a different one of the quadrature component signals with a variable amplification based on the variable amplitude current signal from a different one of the variable current sources to generate an amplitude adjusted quadrature component signal. The combiner combines the amplitude adjusted quadrature component signals from each of the transistor circuits to generate a phase-modulated RF carrier output signal.

A modulating means for modulating and / or demodulating data for transmission from a first device to a second device, wherein the modulating means is capable of modulating and / or demodulating data according to at least a first and a second modulation technique.

The present disclosure relates to using windowing to reduce the bandwidth of an amplitude modulation (AM) power supply input signal (PSIS), which is fed to an AM power supply to provide envelope power to an RF power amplifier stage via an AM power supply output signal. By reducing the bandwidth, noise levels from the AM power supply may be reduced. However, although the bandwidth of the AM PSIS is reduced, the AM power supply output signal may track the AM of the RF power amplifier stage closely enough to meet linearity requirements and to provide high efficiency. The windowing may be based on dividing a stream of AM input samples into a stream of input windows, from which a stream of output windows is created to provide a stream of windowed AM input samples that are used to provide a windowed AM PSIS to the AM power supply.

A transmission circuit for outputting transmission signals with a low distortion and a high efficiency over a wide range of output power is provided. A signal generation section (11) generates an amplitude signal and a phase signal. An angle modulation section (12) performs angle modulation on the phase signal and outputs an angle-modulated signal. A regulator (14) receives the amplitude signal via a variable gain amplification section (18) and supplies a voltage controlled based on the magnitude of the amplitude signal to the amplitude modulation section (15). The amplitude modulation section (15) performs amplitude modulation on the angle-modulated signal and outputs a modulated signal to the variable attenuation section (16). When the value of power information is smaller than a predetermined threshold value, the control section (19) increases the gain of the variable gain amplification section (18) and the attenuation of the variable attenuation section (16).

A modulated optical system with anti-clipping reduces or corrects clipping that might occur in the laser as a result of negative spikes or peaks in a multichannel RF signal. The system generally detects an envelope of the RF signal to generate an anti-clipping signal that follows at least a portion of the envelope and prevents one or more negative peaks from causing clipping by adjusting a bias current in response to the anti-clipping signal. The system may also reduce cross modulation by clamping the anti-clipping signal at an anti-clipping limit during lower power periods of the RF signal.

The invention relates to a device for digital-to-radio frequency conversion, the device comprising: conversion cell matrices for digital-to-radio frequency conversion; means for providing a digital data signal; means for dividing the digital data signal into data signal groups; means for generating clock signals, the clock signals having different phases, the number of clock signals being the same as the number of data signal groups; means for synchronizing the data signal groups by using the clock signals; means for conveying the synchronized data signal groups to the conversion cell matrices, the number of conversion cell matrices being the same as the number of data signal groups; and means for synchronizing each conversion cell matrix by using the clock signal with which the synchronized data signal group conveyed thereto was synchronized for generating interpolation values.