Abstract: An embodiment of the disclosed multichannel receiver may use a single master clock to generate (i) the sampling-clock signal that sets the sampling rate of the receiver's ADC and (ii) multiple electrical local-oscillator signals that are used in various channels of the receiver's analog down-converter to translate to intermediate frequency the RF signals received on the receiver's array of antennas. The multichannel receiver may employ a plurality of interconnected frequency dividers configured to variously divide the master-clock frequency to generate the sampling-clock signal and the multiple local-oscillator signals in a manner that causes these signals to have different respective frequencies.

Abstract: Embodiments of the claimed subject matter provide a method and apparatus for generating a first radio frequency digital signal and providing the first radio frequency digital signal to a radio frequency digital-to-analog converter operating at a sampling frequency. The output of the radio frequency digital-to-analog converter includes a first carrier signal corresponding to the first radio frequency digital signal and having a first frequency below the sampling frequency and an image of the first carrier signal having a second frequency above the sampling frequency. The output of the radio frequency digital-to-analog converter is filtered to select the image of the first carrier signal for transmission.

Abstract: Embodiments of the claimed subject matter provide a method and apparatus for generating a first radio frequency digital signal and providing the first radio frequency digital signal to a radio frequency digital-to-analog converter operating at a sampling frequency. The output of the radio frequency digital-to-analog converter includes a first carrier signal corresponding to the first radio frequency digital signal and having a first frequency below the sampling frequency and an image of the first carrier signal having a second frequency above the sampling frequency. The output of the radio frequency digital-to-analog converter is filtered to select the image of the first carrier signal for transmission.

Abstract: A method for compensating a transceiver for impairments includes transmitting a plurality of partial bandwidth training signals using a transmitter. A plurality of response signals of a receiver having a bandwidth and exhibiting receiver impairments is captured. Each response signal is associated with one of the partial bandwidth training signals. Each of the partial bandwidth training signals is associated with a portion of the receiver bandwidth. A plurality of partial compensation filters is generated based on the plurality of response signals. Each partial compensation filter is associated with one of the response signals. The partial compensation filters are combined to configure a receiver compensation filter operable to compensate for the receiver impairments.

Abstract: Methods and hybrid matrix amplifiers are provided. In a method of calibrating a hybrid matrix amplifier of a wireless transceiver, a plurality of signal paths having a digital and an analog portion are toggled such that the analog portion of each of the plurality of signal paths is active only during a corresponding buffer capture interval of a calibration process. The signal paths carry signals to be transmitted by an antenna arrangement. Channel estimates for each of the plurality of signal paths are generated based only on sampling data collected during the corresponding buffer capture interval. The hybrid matrix amplifier is calibrated based on the generated channel estimates.

Abstract: The present invention provides an amplifier for a wireless transmitter. In one embodiment, the amplifier includes a signal separator for decomposing an input signal into constant envelope signals and amplifier circuits for amplifying the constant envelope signals. The amplifier also includes a combiner for combining the amplified constant envelope signals to form an output signal that is an amplified representation of the input signal. Linear correction circuits are used to apply gain, phase, and/or delay correction to the constant envelope signals. The corrections are determined based upon a feedback portion of the output signal. Pre-distortion circuits are used to apply a non-linear pre-distortion to the constant envelope signals. The non-linear pre-distortion is determined based upon the feedback portion of the output signal.

Abstract: A method for compensating a transceiver for impairments includes transmitting a plurality of partial bandwidth training signals using a transmitter. A plurality of response signals of a receiver having a bandwidth and exhibiting receiver impairments is captured. Each response signal is associated with one of the partial bandwidth training signals. Each of the partial bandwidth training signals is associated with a portion of the receiver bandwidth. A plurality of partial compensation filters is generated based on the plurality of response signals. Each partial compensation filter is associated with one of the response signals. The partial compensation filters are combined to configure a receiver compensation filter operable to compensate for the receiver impairments.

Abstract: The present invention provides an amplifier for a wireless transmitter. In one embodiment, the amplifier includes a signal separator for decomposing an input signal into constant envelope signals and amplifier circuits for amplifying the constant envelope signals. The amplifier also includes a combiner for combining the amplified constant envelope signals to form an output signal that is an amplified representation of the input signal. Linear correction circuits are used to apply gain, phase, and/or delay correction to the constant envelope signals. The corrections are determined based upon a feedback portion of the output signal. Pre-distortion circuits are used to apply a non-linear pre-distortion to the constant envelope signals. The non-linear pre-distortion is determined based upon the feedback portion of the output signal.

Abstract: Methods and hybrid matrix amplifiers are provided. In a method of calibrating a hybrid matrix amplifier of a wireless transceiver, a plurality of signal paths having a digital and an analog portion are toggled such that the analog portion of each of the plurality of signal paths is active only during a corresponding buffer capture interval of a calibration process. The signal paths carry signals to be transmitted by an antenna arrangement. Channel estimates for each of the plurality of signal paths are generated based only on sampling data collected during the corresponding buffer capture interval. The hybrid matrix amplifier is calibrated based on the generated channel estimates.

Abstract: At least one training signal burst is applied to an electronic circuit including an amplifier to train a predistortion circuit associated with the amplifier.

Abstract: In a transmitter, an upconverter converts a lower frequency signal to a higher frequency signal. Prior to the upconversion, a compensator compensates for at least gain/phase distortion that will be introduced into the lower frequency signal by at least the upconverter.

Abstract: The present invention provides a method for selecting samples for digital amplifier predistortion estimation. The method may include accessing a plurality of samples. Each sample includes information associated with an input signal and a corresponding output signal of the amplifier. The method may also include selecting a subset of the plurality of samples based on a sample distribution and determining a transfer function associated with the amplifier based on the subset of the plurality of samples. The method further includes determining a predistortion function based on the transfer function and applying the predistortion function to the input signal of the amplifier.

Abstract: A power control system for a wireless communications system adjusts the transmit power of a wireless transmitter in relation to a number of acknowledgments expected for radio transmissions over a wireless link. For example, a wireless unit monitors the number of acknowledgments it receives (or fails to receive) for radio packets that the wireless unit transmitted over the wireless link. The wireless unit determines the number of acknowledgments lost in relation to the number of acknowledgments expected to be received by the wireless unit. The number of acknowledgments expected by the wireless unit can be based on the number of radio packets transmitted by the wireless unit. If the number of ACKs lost/number of ACKs expected is greater than a first threshold, the wireless unit increases the transmit power level. If the number of ACKs lost/the number of ACKs expected is below a second threshold, the wireless unit decreases the transmit power level.

Abstract: The present invention provides a method for selecting samples for digital amplifier predistortion estimation. The method may include accessing a plurality of samples. Each sample includes information associated with an input signal and a corresponding output signal of the amplifier. The method may also include selecting a subset of the plurality of samples based on a sample distribution and determining a transfer function associated with the amplifier based on the subset of the plurality of samples. The method further includes determining a predistortion function based on the transfer function and applying the predistortion function to the input signal of the amplifier.

Abstract: A method may include determining a power level of a signal and a temperature level of a transmitter originating the signal. At least one of the power and temperature levels may be compared to a lookup table containing predistortion coefficients. The method is capable of predistorting a signal based on the comparison. An apparatus is disclosed in relation to the method.

Abstract: A power control system for a wireless communications system adjusts the transmit power of a wireless transmitter in relation to a number of acknowledgments expected for radio transmissions over a wireless link. For example, a wireless unit monitors the number of acknowledgments it receives (or fails to receive) for radio packets that the wireless unit transmitted over the wireless link. The wireless unit determines the number of acknowledgments lost in relation to the number of acknowledgments expected to be received by the wireless unit. The number of acknowledgments expected by the wireless unit can be based on the number of radio packets transmitted by the wireless unit. If the number of ACKs lost/number of ACKs expected is greater than a first threshold, the wireless unit increases the transmit power level. If the number of ACKs lost/the number of ACKs expected is below a second threshold, the wireless unit decreases the transmit power level.

Abstract: In a transmitter, an upconverter converts a lower frequency signal to a higher frequency signal. Prior to the upconversion, a compensator compensates for at least gain/phase distortion that will be introduced into the lower frequency signal by at least the upconverter.

Abstract: At least one training signal burst is applied to an electronic circuit including an amplifier to train a predistortion circuit associated with the amplifier.

Abstract: A method may include determining a power level of a signal and a temperature level of a transmitter originating the signal. At least one of the power and temperature levels may be compared to a lookup table containing predistortion coefficients. The method is capable of predistorting a signal based on the comparison. An apparatus is disclosed in relation to the method.

Abstract: A transmitter module is provided that includes a discrete-coefficients phase-combiner and an analog-coefficients phase combiner sandwiched on either side of a middle section having at least a bank of up-converters and a bank of amplifiers. Despite a transmission scenario changing, e.g., by the addition of another carrier frequency, it is not necessary to replace the transmitter module with new equipment. Rather, the transmitter module can be retained and reused in combination with an additional transmitter module whose software aspects (discrete-coefficients phase-combiner) can be tuned so that the transfer function of the additional transmitter module matches the transfer function of the retained transmitter module.