Abstract: Embodiments include methods for determining intermodulation distortion (IMD) present in an uplink channel received by a network node in a wireless communication network. Such embodiments include, for each of a plurality of time period pairs comprising first and second time periods: measuring a first parameter for an uplink channel received and a second parameter for each of a plurality of downlink channels transmitted by the network node; and for the uplink channel, determining a first difference between the first parameter measured during the first time period and the first parameter measured during the second time period. Such embodiments also include, based on the first difference and the second parameters, determining a predictive model for an IMD signal, associated with the downlink channels, that can be received by the network node in the uplink channel. For example, the predictive model can be used to adjust transmitter settings to improve IMD performance.

Abstract: A method and network node for detection of passive intermodulation (PIM) are disclosed. According to one aspect, a method includes determining values of a covariance matrix based at least in part on uplink signals received by the network node radio. The method also includes determining a plurality of uplink (UL) channel 5 eigenvalues based at least in part on an eigen-component acquisition technique. The method further includes determining a presence or absence of PIM based at least in part on a plurality of the UL channel eigenvalues.

Abstract: A method and apparatus for artificial neural network precoding for massive MIMO systems are disclosed. In one embodiment, a method includes processing, by an artificial neural network, ANN, precoding engine, at least one input signal by 5 performing a low peak-to-average-power ratio, PAPR, precoding on the at least one input signal; and transmitting, via at least one antenna array having at least one antenna, at least one precoded output signal processed by the ANN precoding engine.

Abstract: Embodiments include methods for determining intermodulation distortion (IMD) present in an uplink channel received by a network node in a wireless communication network. Such embodiments include, for each of a plurality of time period pairs comprising first and second time periods: measuring a first parameter for an uplink channel received and a second parameter for each of a plurality of downlink channels transmitted by the network node; and for the uplink channel, determining a first difference between the first parameter measured during the first time period and the first parameter measured during the second time period. Such embodiments also include, based on the first difference and the second parameters, determining a predictive model for an IMD signal, associated with the downlink channels, that can be received by the network node in the uplink channel. For example, the predictive model can be used to adjust transmitter settings to improve IMD performance.

Abstract: A method and network node for detection of passive intermodulation (PIM) are disclosed. According to one aspect, a method includes determining values of a covariance matrix based at least in part on uplink signals received by the network node radio. The method also includes determining a plurality of uplink (UL) channel 5 eigenvalues based at least in part on an eigen-component acquisition technique. The method further includes determining a presence or absence of PIM based at least in part on a plurality of the UL channel eigenvalues.

Abstract: A method and apparatus for artificial neural network precoding for massive MIMO systems are disclosed. In one embodiment, a method includes processing, by an artificial neural network, ANN, precoding engine, at least one input signal by 5 performing a low peak-to-average-power ratio, PAPR, precoding on the at least one input signal; and transmitting, via at least one antenna array having at least one antenna, at least one precoded output signal processed by the ANN precoding engine.

Abstract: Systems and methods are disclosed herein that related to Peak-to-Average Power Ratio (PAPR) reduction in a (e.g., massive) Multiple-Input Multiple-Output (MIMO) Orthogonal Division Multiplexing (OFDM) transmitter system. In some embodiments, a method of operation of a MIMO OFDM transmitter system comprises, for each carrier of two or more carriers, performing precoding of a plurality of frequency-domain input signals for the carrier to provide a plurality of frequency-domain precoded signals for the carrier, the plurality of frequency-domain input signals for the carrier being for a plurality of transmit layers for the carrier, respectively. The method further comprises processing the frequency-domain precoded signals for the two or more carriers in accordance with a multi-carrier Convex Reduction of Amplitudes (CRAM) processing scheme to provide a plurality of multi-carrier time-domain transmit signals for a plurality of antenna branches, respectively, of the MIMO OFDM transmitter system.

Abstract: Systems and methods are disclosed herein that related to Peak-to-Average Power Ratio (PAPR) reduction in a (e.g., massive) Multiple-Input Multiple-Output (MIMO) Orthogonal Division Multiplexing (OFDM) transmitter system. In some embodiments, a method of operation of a MIMO OFDM transmitter system comprises, for each carrier of two or more carriers, performing precoding of a plurality of frequency-domain input signals for the carrier to provide a plurality of frequency-domain precoded signals for the carrier, the plurality of frequency-domain input signals for the carrier being for a plurality of transmit layers for the carrier, respectively. The method further comprises processing the frequency-domain precoded signals for the two or more carriers in accordance with a multi-carrier Convex Reduction of Amplitudes (CRAM) processing scheme to provide a plurality of multi-carrier time-domain transmit signals for a plurality of antenna branches, respectively, of the MIMO OFDM transmitter system.

Abstract: Embodiments of a transmitter having an architecture that reduces power consumption and complexity are disclosed. In some embodiments, a transmitter comprises a modulator comprising an actuator, modulation circuitry, and an adaptor. The actuator is operable to apply at least one adjustment to at least one modulator input signal to provide at least one adjusted modulator input signal. The modulation circuitry is operable to perform a modulation operation on the at least one adjusted modulator input signal to provide a modulated signal, and the adaptor is operable to adaptively configure the at least one adjustment applied to the at least one modulator input signal such that a Peak-to-Average Ratio (PAR) of the modulated signal is reduced.

Abstract: Embodiments of a system and a method of operation of the system to reduce Peak-to-Average Power Ratio (PAPR) in an input signal for transmission over one or more carriers are disclosed. In some embodiments, the method of operation of the wireless transmission system comprises configuring a frequency-domain mask such that, for each subcarrier of a plurality of subcarriers of a carrier of the input signal, a value in the frequency-domain mask for the subcarrier is a function of a modulation scheme utilized in the input signal for the subcarrier. The method further comprises transforming the frequency-domain mask into a time-domain pulse and utilizing the time-domain pulse according to a pulse injection scheme to reduce a PAPR of the input signal.

Abstract: Embodiments of a transmitter having an architecture that reduces power consumption and complexity are disclosed. In some embodiments, a transmitter comprises a modulator comprising an actuator, modulation circuitry, and an adaptor. The actuator is operable to apply at least one adjustment to at least one modulator input signal to provide at least one adjusted modulator input signal. The modulation circuitry is operable to perform a modulation operation on the at least one adjusted modulator input signal to provide a modulated signal, and the adaptor is operable to adaptively configure the at least one adjustment applied to the at least one modulator input signal such that a Peak-to-Average Ratio (PAR) of the modulated signal is reduced.

Abstract: A method, system and apparatus for modelling a power amplifier and pre-distorter fed by one of a wideband signal and an intra-band carrier aggregated signal are disclosed. According to one aspect, a method includes receiving the one of the wideband signal and the intra-band carrier aggregated signal and generating a discrete base band equivalent, BBE, Volterra series based on the received signal, where the series has distortion products grouped according to determined shared kernels. The shared kernels are determined based on a transformation of a real-valued continuous-time pass band Volterra series without pruning of kernels.

Abstract: Methods, systems and apparatus for modelling a power amplifier and pre-distorter fed by a multi-band signal are disclosed. According to one aspect, a method includes receiving a multi-band signal and generating a discrete base band equivalent, BBE, Volterra series based on the received multi-band signal, where the series has distortion products grouped according to determined shared kernels. The shared kernels are determined based on a transformation of a real-valued continuous-time pass band Volterra series without pruning of kernels.

Abstract: Systems and methods for providing multiband predistortion using a time-shared adaptation loop are disclosed. In some embodiments, a multiband predistortion system includes a multiband power amplifier for amplifying N separate bands, a predistortion system including N Digital Predistorters (DPDs), and a single adaptation loop capable of providing predistorter adaptation for the N separate bands. The single adaptation loop includes at least one Training Engine (TE) module where the number of TE modules is less than N, and at least one Transmission Observation Receiver (TOR) module where the number of TOR modules is less than N. In this way, the cost and complexity of the multiband predistortion system can be reduced.

Abstract: The present disclosure advantageously provides methods and systems for crest factor reduction of multi-standard carrier aggregated signals. In one embodiment, a method of providing crest factor reduction for a carrier aggregated signal is provided. In one embodiment, the method comprises estimating a peak of a carrier aggregated signal based on a summation of instantaneous amplitudes of baseband representations of a number of component carriers of the carrier aggregated signal. The number of component carriers of the carrier aggregated signal is greater than or equal to 2. The method further comprises clipping the baseband representations of the component carriers if the estimated peak of the carrier aggregated signal is greater than a predefined clipping threshold.

Abstract: A method, system and apparatus for modelling a power amplifier and pre-distorter fed by one of a wideband signal and an intra-band carrier aggregated signal are disclosed. According to one aspect, a method includes receiving the one of the wide-band signal and the intra-band carrier aggregated signal and generating a discrete base band equivalent, BBE, Volterra series based on the received signal, where the series has distortion products grouped according to determined shared kernels. The shared kernels are determined based on a transformation of a real-valued continuous-time pass band Volterra series without pruning of kernels.

Abstract: Methods, systems and apparatus for modelling a power amplifier and pre-distorter fed by a multi-band signal are disclosed. According to one aspect, a method includes receiving a multi-band signal and generating a discrete base band equivalent, BBE, Volterra series based on the received multi-band signal, where the series has distortion products grouped according to determined shared kernels. The shared kernels are determined based on a transformation of a real-valued continuous-time pass band Volterra series without pruning of kernels.

Abstract: A method, system and circuit for crest factor reduction of inter-band multi-standard carrier aggregated signals are disclosed. In one embodiment, a method includes calculating the amplitude of each of the plurality of carrier signals of the inter-band carrier aggregated signals. An estimate of an envelope of a combination of the carrier signals is produced based on a sum of the calculated amplitudes of the plurality of carrier signals. The estimate of the envelope of the combination of the carrier signals is compared to a clipping threshold to determine whether to clip each of the plurality of carrier signals.

Abstract: A method, system and circuit for crest factor reduction of inter-band multi-standard carrier aggregated signals are disclosed. In one embodiment, a method includes calculating the amplitude of each of the plurality of carrier signals of the inter-band carrier aggregated signals. An estimate of an envelope of a combination of the carrier signals is produced based on a sum of the calculated amplitudes of the plurality of carrier signals. The estimate of the envelope of the combination of the carrier signals is compared to a clipping threshold to determine whether to clip each of the plurality of carrier signals.

Abstract: The present disclosure advantageously provides methods and systems for crest factor reduction of multi-standard carrier aggregated signals. In one embodiment, a method of providing crest factor reduction for a carrier aggregated signal is provided. In one embodiment, the method comprises estimating a peak of a carrier aggregated signal based on a summation of instantaneous amplitudes of baseband representations of a number of component carriers of the carrier aggregated signal. The number of component carriers of the carrier aggregated signal is greater than or equal to 2. The method further comprises clipping the baseband representations of the component carriers if the estimated peak of the carrier aggregated signal is greater than a predefined clipping threshold.