1006results about "Modulation transference" patented technology

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. Briefly stated, such methods, systems, and apparatuses operate by receiving an EM signal and an aliasing signal having an aliasing rate. The EM signal is aliased according to the aliasing signal to down-convert the EM signal. The term aliasing, as used herein, refers to both down-converting an EM signal by under-sampling the EM signal at an aliasing rate, and down-converting an EM signal by transferring energy from the EM signal at the aliasing rate. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a demodulated baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

A novel mechanism for simultaneous multiple signal reception and transmission using frequency multiplexing and shared processing. Multiple RF signals, which may be of various wireless standards, are received using one or more shared processing blocks thereby significantly reducing chip space and power requirements. Shared components include local oscillators, analog to digital converters, digital RX processing and digital baseband processing. In operation, multiple RX front end circuits, one for each desired wireless signal, generate a plurality of IF signals that are frequency multiplexed and combined to create a single combined IF signal. The combined IF signal is processed by a shared processing block. Digital baseband processing is performed on each receive signal to generate respective data outputs. Further, simultaneous full-duplex transmission and reception is performed using a single local oscillator. The phase / frequency modulation of the frequency synthesizer used in the TX is removed from the local oscillator signal for use in the receiver.

A communication system comprising a multi-protocol, multi-bearer sub-system is described herein. The sub-system is a universal platform module that can transmit and receive one or more information signals in one or more protocols using one or more bearer services. In one embodiment, the sub-system may form a portion of a transceiver that is composed of a transmitter and a receiver, and which is a gateway server between a personal area network (PAN) and the global wireless network.

Methods and apparatuses for frequency selectivity and frequency translation, and applications for such methods and apparatuses, are described herein. The method includes steps of filtering an input signal, and down-converting the filtered input signal. The filtering and the down-conversion operations are performed in an integrated, unified manner. The apparatus described herein can be implemented as an integrated circuit (IC).

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. Briefly stated, such methods, systems, and apparatuses operate by receiving an EM signal and an aliasing signal having an aliasing rate. The EM signal is aliased according to the aliasing signal to down-convert the EM signal. The term aliasing, as used herein, refers to both down-converting an EM signal by under-sampling the EM signal at an aliasing rate, and down-converting an EM signal by transferring energy from the EM signal at the aliasing rate. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a demodulated baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

The present invention includes a system and method for ensuring reception of a communications signal. A modulating baseband signal with desired information is accepted, and a plurality of redundant spectrums is generated. Each redundant spectrum comprises the necessary amplitude, phase, and frequency information to substantially reconstruct the modulating baseband signal. It is expected but not required that the redundant spectrums will be generated at a first location and sent to a second location over a communications medium. At the second location, the redundant spectrums are independently processed to recover a demodulating baseband signal for each of the redundant spectrums. In one embodiment, an error detection process is employed at the second location to detect and eliminate those demodulated baseband signals that have been corrupted during transmission. An error-free demodulated baseband signal is selected from the remaining demodulated baseband signals. The error-free demodulated baseband signal is representative of the modulating baseband signal sent over the communications medium.

Methods and apparatuses for frequency selectivity and frequency translation, and applications for such methods and apparatuses, are described herein. The method includes steps of filtering an input signal, and down-converting the filtered input signal. The filtering and the down-conversion operations are performed in an integrated, unified manner. The apparatus described herein can be implemented as an integrated circuit (IC).

Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and / or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and / or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

A quadrature amplitude demodulator demodulates a modulated signal on which quadrature amplitude modulation is performed. Oscillators generate an in-phase carrier signal having a rectangular wave, a trapezoidal wave or a waveform similar to these, and a quadrature carrier signal, the phase of which is shifted by ¼ cycle relative to the in-phase signal. First and second mixers respectively perform mixing of the modulated signal with the in-phase signal and the quadrature carrier signal. First and second integrators respectively integrate output signals of the first and the second mixers, for a predetermined period in accordance with the cycle of the in-phase carrier signal and the quadrature carrier signal. First and second A / D converters respectively convert outputs of the first and the second integrators into digital values.

Methods and apparatuses for frequency selectivity and frequency translation, and applications for such methods and apparatuses, are described herein. The method includes steps of filtering an input signal, and down-converting the filtered input signal. The filtering and the down-conversion operations are performed in an integrated, unified manner. The apparatus described herein can be implemented as an integrated circuit (IC).

A receiver can be configured to include an RF front end that is configured to downconvert a received signal to a baseband signal or a low Intermediate Frequency (IF) signal. The receiver can downconvert the desired signal from an RF frequency in the presence of numerous interference sources to a baseband or low IF signal for filtering and channel selection. The filtered baseband or low IF signal can be converted to a digital representation. The digital representation of the signal can be upconverted in the digital domain to a programmable IF frequency. The digital IF signal can be converted to an analog IF signal that can be processed by legacy hardware.

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

Methods and apparatus are described herein that make use of complex tuning, the inherently repetitive nature of sampled signals, and programmable digital filtering to create a flexible digital up-conversion system that utilizes a digital-to-analog converter (DAC) with a fixed effective sample rate while still being adapted for tunability over a wide frequency range. With a knowledge of the fixed effective sample rate of the DAC and a desired frequency of up-conversion and combining complex tuning at baseband and up-sampling by a factor of N with a programmable passband filter configured to select one of a plurality of signal images resulting from the up-sampling, it is possible to translate a baseband input signal to a wide range of frequencies above or below Fs, without changing the sampling rate of the fixed rate DAC used in the up-conversion process.

A differential radio frequency signal transmitter is provided. The differential radio frequency signal transmitter includes an oscillator, a modulator and an amplifier module. The oscillator generates a pair of differential oscillation signals. The modulator generates a pair of differential modulated signals according to an input signal and the pair of differential oscillation signals. The input signal is a digital signal. When the input signal is at a first state, the modulator outputs the pair of differential oscillation signals as the pair of differential modulated signals, and when the input signal is at a second state, the modulator outputs a constant voltage signal as the pair of differential modulated signals. The amplifier module receives and amplifies the pair of differential modulated signals and generates a pair of differential radio frequency signals, accordingly.

A receiver system and a demodulator system are configured to receive and demodulate, respectively, multi-gigabit millimeter wave signals being wirelessly transmitted in the unlicensed wireless band near 60 GHz.

An N-phase radio receiver front-end for converting an input signal having a first frequency to output signals having a second frequency, and a method for converting an input signal in an N-phase radio receiver front-end. An input port of the N-phase radio receiver front-end is directly connected to an input port of a low noise amplifier (50). A mixer arrangement (50a) is a current mode mixer arrangement. An output port of the low-noise amplifier is directly connected to an input port of the mixer arrangement. A signal generator operatively connected to the mixer arrangement is adapted to generate N phase shifted local oscillator signals.

A method and system for converting an optical signal to electrical information signals, including demodulated baseband information signals and modulated baseband signals at multiple harmonics. In an embodiment, the optical information signal is amplitude modulated with information. The method converts an optical signal to electrical charge, accumulates the electrical charge, and periodically transfers the accumulated electrical charge to a storage device, whereby the periodically transferred electrical charge forms the electrical signals. An exemplary system includes an optical transducer and a universal frequency translator coupled to an output of the optical transducer. The optical transducer receives an optical signal and converts the optical signal to electrical charge. The universal frequency translator periodically transfers energy from the electrical charge and forms the electrical signals from the transferred energy. In an embodiment, the present invention converts an I and Q optical signal to electrical signals. In an embodiment, the present invention converts an optical signal to an RF electrical signal using relatively few components, while preserving information content.

The present disclosure relates to systems, devices and methods related to transmitters, and / or transceivers having a single, tunable oscillator in a dual conversion architecture. In various exemplary embodiments, this transmitter may include: a first mixer configured to receive a first oscillator signal from the single oscillator; a filter configured to band pass filter the converted signal and output a filtered signal; and a second mixer in communication with the filter, configured to receive the filtered signal. This dual conversion transmitter may be configured to receive a communication signal from an input to the transmitter and to output a converted signal based on the first oscillator signal and the communication signal. The second mixer may be configured to receive a scaled version of the first oscillator signal and to output a desired frequency output signal based on the scaled version of the first oscillator signal and the filtered signal.

A high performance radio frequency receiver includes a low noise amplifier with large binary and stepped gain control range, controlled impedance, and enhanced blocker immunity, for amplifying and converting a radio frequency signal to a current; a pulse generator for generating in-phase and quadrature pulses; a crossover correction circuit and pulse shaper for controlling a crossover threshold of the pulses and interaction between in-phase and quadrature mixers; and a double balanced mixer for combining the RF signal with the pulses to generate an intermediate frequency or baseband zero intermediate frequency current-mode signal. The in-phase and quadrature pulses have a duty cycle of 20-35%. The intermediate frequency signal and second order harmonics may be filtered with a high frequency low pass filter and a current injected complex direct-coupled filter. Decreased die size, current drain, cost, and complexity, as well as improvements in gain, 1 / f noise, noise figure, sensitivity, and linearity may result.

An RF transceiver integrated circuit has a novel segmented, low parasitic capacitance, internal loopback conductor usable for conducting IP2 self testing and / or calibration. In a first novel aspect, the transmit mixer of the transceiver is a current mode output mixer. The receive mixer is a passive mixer that has a low input impedance. In the loopback mode, the transmit mixer drives a two tone current signal to the passive mixer via the loopback conductor. In a second novel aspect, only one quadrature branch of the transmit mixer is used to generate both tones required for carrying out an IP2 test. In a third novel aspect, a first calibration test is performed using one quadrature branch of the transmit mixer at the same time that a second calibration test is performed using the other quadrature branch, thereby reducing loopback test time and power consumption.

A downconverter and upconverter are provided which can obtain a satisfactory image rejection ratio in a low-Intermediate Frequency (IF) scheme while reducing power consumption, and can improve Error Vector Magnitude (EVM) in a zero-IF scheme. A complex-coefficient transversal filter rejects one side of a positive or negative frequency, and converts a Radio Frequency (RF) signal to a complex RF signal configured by real and imaginary parts. A local oscillator outputs a complex local signal in which a set frequency is set as a center frequency. A full-complex mixer, connected to the complex-coefficient transversal filter and the local oscillator, perform a frequency conversion process by multiplying a complex signal output from the complex-coefficient transversal filter and the complex local signal output from the local oscillator, and outputs a complex signal of a frequency separated by the set frequency from a frequency of the RF signal.

A novel and useful channel tracking mechanism operative to generate channel estimate updates on blocks of samples during reception of a message. The tracking mechanism is based on the weighted recursive least squares algorithm and implements the estimation process by recursively updating channel model parameters upon the arrival of new sample data. The mechanism is operative to update channel estimate information once per sample block. An interblock exponential weighting factor is also applied. The block length is chosen short enough to enable good tracking performance while being sufficiently long enough to minimize the overhead of generating preliminary decisions and of updating precalculated tables in the equalizer. The method of the invention can be performed in either hardware or software. A computer comprising a processor, memory, etc. is operative to execute software adapted to perform the channel tracking method of the present invention.

A receiver (1100) includes a direct digital frequency synthesizer (130), a mixer (105), and a clock source (1110, 1130). The direct digital frequency synthesizer has an input terminal for receiving a first clock signal at a first frequency, and an output terminal for providing a digital local oscillator signal synchronously with the first clock signal. The mixer (105) has a first input terminal for receiving a radio frequency (RF) signal, a second input terminal coupled to the output terminal of the direct digital frequency synthesizer (130), and an output terminal for providing an IF signal having a spectrum centered about a selectable one of a plurality of center frequencies. The clock source (1110, 1130) has an output terminal for providing the first clock signal without using any harmonic frequency that overlaps the spectrum for any of the plurality of center frequencies.

An RF transmitter capable of transmitting over a wide range of frequencies includes a mixer, a wideband high-Q balun, a first driver amplifier and a second driver amplifier. The balun has a single primary winding and two secondary windings. A differential output of the mixer is coupled to the primary winding. A first of the two secondary windings is coupled to drive the first driver amplifier. A second of the two secondary windings is coupled to drive the second driver amplifier. One driver amplifier is used when transmitting at lower frequencies whereas the other driver amplifier is used when transmitting at higher frequencies. By appropriate sizing of the inductances of the secondary windings and by switching out one of the secondary windings at certain times, the balun is tunable to operate over the wide frequency range while having a high quality factor Q, thereby facilitating reduced power consumption while simultaneously meeting performance requirements.

The invention discloses an all digital frequency converting method and a device thereof, being easily realized for hardware. The method and the device are essentially used for sample rate convertion of rational number-times of baseband signals and the convertion of the baseband signals and the intermediate frequency signals in digital communication. Under the coordination of control signals and enabling signals, the convertion of signal sample rate can be finished and the convertion of the baseband signals and the intermediate signals can be finished through the reasonable matching of variable integral number-times wave filtering and fraction-times interpolation. The system of the invention essentially comprises a frequency mixer, a cascade connection integral comb filter, a fraction-time interpolating device, a half-band filter, a signal shaping filter, a power detection module and a control interface. The configurable hardware implemented structure of the invention is applicable to a plurality of modulation methods, has the advantages of low resource consumption and good portability, and is used for various wireless communication systems such as multilevel phase shift keying (MPSK), orthogonal frequency division multiplex (OFDM), direct sequence spread spectrum (DSSS) and continuous phase modulation (CPM), etc.

Transmitter architectures designed to accommodate both constant and non-constant of envelope modulation schemes and capable of providing local oscillator carrier frequencies within any one of numerous desired frequency bands, thus allowing compliance with many different communication standards. One example of a programmable frequency synthesizer includes a plurality of transmitter components and a microcontroller coupled to the frequency synthesizer and to the plurality of transmitter components. The microcontroller is adapted to provide a frequency control signal to the frequency synthesizer to control a frequency of the local oscillator carrier frequency. In addition, the microcontroller is also adapted to provide digital control signals to at least some of the plurality of transmitter components to turn on and off different ones of the plurality of transmitter components based on an operating mode of the transmitter, such that the transmitter can accommodate both constant envelope modulation and non-constant envelope modulation schemes.

A receiver (200) includes a transconductance mixer (310), a polyphase filter (320), and a transimpedance amplifier (330). The transconductance mixer (310) mixes a radio frequency (RF) voltage signal into a current signal having a plurality of phases using a local oscillator signal. The polyphase filter (320) filters the current signal to provide a filtered current signal. The transimpedance amplifier (330) converts the filtered current signal into an output voltage signal.