Abstract: A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

Abstract: A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

Abstract: A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

Abstract: A novel and useful apparatus and method for an image-interferer aware single quadrature RF downconversion (SQRD) low intermediate frequency (LIF) receiver and related power reduction techniques utilized therein. The invention applies zero-margin adaptive transceiver (ZMAT) design principles to considerably reduce the receiver's power consumption in an adaptive fashion in accordance with the instantaneous reception conditions. In a low IF dual-branch (i.e. quadrature) downconversion receiver, the radio monitors the image strength and shuts off the receiver's Q branch (or I branch) when image rejection is not needed (i.e. when the relative image strength is below a threshold), thus significantly reducing power consumption in the RF receiver. A zero IF receiver is switched to a SQRD low IF receiver of lower power consumption when the image interferer strength is low enough to allow for a given required level of performance.

Abstract: A digital wireless transmitter and a method of transmitting a high-power modulated RF signal using a digital wireless transmitter are provided. In one embodiment, the transmitter includes: a digital system-on-a-chip configured to receive a complex digital input signal and having: an all-digital phase-locked loop and digital pulse modulator configured to modulate a phase and frequency modulation signal based on the complex digital input signal to yield a modulated complex signal, a driver configured to generate a pulse-position-modulated and pulse-width-modulated pulse train based on an instantaneous phase and amplitude of the modulated complex signal and a power supply modulation control block configured to develop an amplitude modulation control signal based on the complex digital input signal that defines a non-constant-envelope for an output signal of the transmitter.

Abstract: A digital wireless transmitter and a method of transmitting a high-power modulated RF signal using a digital wireless transmitter. In one embodiment, the transmitter includes: (1) a digital system-on-a-chip configured to receive a complex digital input signal and having: (1a) an all-digital phase-locked loop and digital pulse modulator configured to modulate a phase and frequency modulation signal based on the complex digital input signal to yield a modulated complex signal, (1b) a driver configured to generate a pulse-position-modulated and pulse-width-modulated pulse train based on an instantaneous phase and amplitude of the modulated complex signal and (1c) a power supply modulation control block configured to develop an amplitude modulation control signal based on the complex digital input signal that defines a non-constant-envelope for an output signal of the transmitter.

Abstract: An apparatus and method of linearization of a digitally-controlled pre-power amplifier (DPA) and RF power amplifier (PA) for performing predistortion calibration to compensate for nonlinearlities in the DPA and PA circuits. A predistortion look up table (LUT) stores measured distortion compensation data that is applied to the TX data before being input to the digital-to-frequency converter (DFC), DPA and PA. The on-chip receiver, which is normally inactive during the TX burst in a half-duplex operation, demodulates the RF PA output and uses the digital I/Q RX outputs to perform calibration of the TX pre-distortion tables. A sample of the RF output signal is provided to the receiver chain. While the PA (DPA) code is increasing (or decreasing), the amplitude and phase of the recovered I/Q samples are used to determine the instantaneous value of the AM/AM and AM/PM pre-distortion from which an update to the predistortion tables may be computed.

Abstract: A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using a modified modulation scheme, which adds phase modulation over the legacy amplitude modulation, such as the legacy WWVB pulse width modulated (PWM)/amplitude shift keying (ASK) modulation, thereby allowing for improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK).

Abstract: A novel and useful multi-antenna receiver that receives, demodulates and decodes a broadcast signal, whose modulation and encoding of time and timing information allow for reliable and power-efficient operation. The multi-antenna receiver of the present invention is adapted to eliminate or substantially reduce the reception nulls that occur in receivers having a single antenna that is placed in a fixed position. Two or more antennas are employed whereby the receiver generates a combined signal based on a combination of the individual antenna signals or selects one of the antenna signals for input to the receiver based on desired criteria such as signal-to-noise-and-interference-ratio (SNIR). This results in greater robustness of the communication link by reducing or eliminating reception nulls and by rejecting interference through the selection of the antenna for which the signal-to-interference ratio is higher.

Abstract: Cost-effective structures and methods that allow an integrated digital-to-analog converter (DAC) to simultaneously achieve wide dynamic ranges and bandwidths through the use of built-in measurement and compensation mechanisms that are primarily digital. The measurements of the DAC's distortions are made with a relatively simple analog-to-digital converter (ADC) that is not designed to accommodate the combination of the bandwidth and the resolution offered by the DAC, but is nonetheless sufficient in determining the characteristics of the DAC's impairments during a calibration procedure. This information is then used in a feed-forward compensation system during the DAC's normal operation to estimate and cancel the distortions in its output signal that could result from the various impairments.

Abstract: A configurable system and method for a radio controlled clock (RCC) receiver adapted to apply different strategies for extracting timing and time information from a phase modulated signal depending on the type of application the RCC is used in and on the reception conditions. The official time signal is broadcast from a central location using a modulation scheme which includes phase modulation that alternates between different information rates, allowing for multiple alternative reception modes that are suited for different ranges of signal-to-interference-and-noise-ratio (SINR). The operation of the RCC is configured by the application that hosts it, such that the reception performance and the energy consumption best suit that application. The reception mode used by the RCC at a given time may be selected automatically, i.e. without user intervention, based on the device's profile of operation and the reception conditions.

Abstract: A method of cancelling alien noise in coordinated DSL lines, a method of smoothing an alien noise covariance estimate, and a processor and modem for cancelling alien noise in coordinated DSL lines. In one embodiment, the method of cancelling alien noise includes: (1) estimating alien noise vectors for at least some training symbols, (2) arranging the alien noise vectors in a matrix dimensioned for a number of coordinated DSL lines, (3) orthonormally transforming the matrix into a lower-triangular matrix and (4) computing alien noise prediction filters from the lower-triangular matrix.

Abstract: Cost-effective structures and methods that allow an integrated digital-to-analog converter (DAC) to simultaneously achieve wide dynamic ranges and bandwidths through the use of built-in measurement and compensation mechanisms that are primarily digital. The measurements of the DAC's distortions are made with a relatively simple analog-to-digital converter (ADC) that is not designed to accommodate the combination of the bandwidth and the resolution offered by the DAC, but is nonetheless sufficient in determining the characteristics of the DAC's impairments during a calibration procedure. This information is then used in a feed-forward compensation system during the DAC's normal operation to estimate and cancel the distortions in its output signal that could result from the various impairments.

Abstract: A timekeeping device that tracks the time provided by a digital broadcast and the protocol of that broadcast, defined by its data frame structure and modulation scheme, are adapted to allow for superior performance of the timekeeping devices in terms of range of operation, immunity to interference, ability to operate with lower cost antennas due to enhanced link robustness, and reduced energy consumption. The timekeeping device operates with infrequent receptions of the broadcast by relying on independent self-compensation. This alleviates the need for frequent receptions to ensure timing accuracy while reducing energy consumption. The mean and variability of successive measurements of timing drift are evaluated and an estimated upper bound for the drift-estimation error is set. Based on this bound, the device employs a reception strategy that relies on less frequent receptions, corresponding to the error in estimating the drift rather than to the magnitude of the drift itself.

Abstract: A novel and useful multi-antenna receiver that receives, demodulates and decodes a broadcast signal, whose modulation and encoding of time and timing information allow for reliable and power-efficient operation. The multi-antenna receiver of the present invention is adapted to eliminate or substantially reduce the reception nulls that occur in receivers having a single antenna that is placed in a fixed position. Two or more antennas are employed whereby the receiver generates a combined signal based on a combination of the individual antenna signals or selects one of the antenna signals for input to the receiver based on desired criteria such as signal-to-noise-and-interference-ratio (SNIR). This results in greater robustness of the communication link by reducing or eliminating reception nulls and by rejecting interference through the selection of the antenna for which the signal-to-interference ratio is higher.

Abstract: Various embodiments of a method of mitigating interference in an OFDMA cellular network and a user terminal incorporating various of the embodiments. In one embodiment, the method includes: (1) selecting at least one dominant interfering signal, (2) generating estimates of a desired signal and the at least one dominant interfering signal, (3) jointly deciding based on the estimates such that an energy of a residual error is reduced and (4) mitigating interference based on the estimates.

Abstract: A novel and useful system and method for leap second and daylight saving time (DST) correction for use in a radio controlled clock (RCC) receiver. The RCC receiver extracts schedule information from the frame, including the time for the DST transition and whether a leap second needs to be added at the end of this half-year. Linear error correcting coding is used for the leap second and the DST on/off indications, while non-linear error correcting coding (e.g., a look up table) is used for the DST schedule to enhance reception reliability in the presence of noise and interference. The one second/one hour corrections are scheduled to occur when they should take place and the correction is applied exactly when DST or leap second is to go into effect, without having to receive anything around the time of the correction.

Abstract: A novel and useful apparatus for and method of predistortion calibration and built-in self testing (BIST) of a nonlinear digitally-controlled radio frequency (RF) power amplifier (DPA) using subharmonic mixing. The RF power amplifier output is temporarily coupled into the frequency reference (FREF) input and the phase error samples generated in the phase locked loop (PLL) are then observed and analyzed. The digital predistortion and BIST mechanisms process the phase error samples to calibrate and test the DPA in the transmitter of the Digital RF Processor (DRP). The invention enables the characterization of nonlinearities, the configuration of internal predistortion, as well as the testing of the transmitter's analogRF circuitry, thereby eliminating commonly employed RF performance testing using high-cost test equipment and associated extended test times.

Abstract: A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using a modified modulation scheme, which adds phase modulation over the legacy amplitude modulation, such as the legacy WWVB pulse width modulated (PWM)/amplitude shift keying (ASK) modulation, thereby allowing for improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK).

Abstract: A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using the modified modulation scheme of the present invention, which adds phase modulation that allows for greatly improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK). A superframe comprising multiple frames with repeated information allows for the accumulation of received energy over multiple frames to provide for a corresponding gain in the receiver.