Abstract: A receiver comprising a signal phase shifting block generating concurrent phase shifted copies of an input signal, and an impedance translation function block configured to receive the phase shifted copies of the input signal and generate a down converted signal wherein the impedance translation function block is driven by a single clock signal of frequency determined by a desired carrier frequency. The receiver including an energy harvesting block coupled to the phase shifting block to receive one or more in-band or out-of-band interferers in the input signal and reflected signals from the impedance translation function block due to nonlinearities.

Abstract: A receiver comprising a signal phase shifting block generating concurrent phase shifted copies of an input signal, and an impedance translation function block configured to receive the phase shifted copies of the input signal and generate a down converted signal wherein the impedance translation function block is driven by a single clock signal of frequency determined by a desired carrier frequency. The receiver including an energy harvesting block coupled to the phase shifting block to receive one or more in-band or out-of-band interferers in the input signal and reflected signals from the impedance translation function block due to nonlinearities.

Abstract: A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

Abstract: A radio communication system for duplex communication comprising an optical carrier generator for generating optical carrier signals, a local oscillator (LO) for generating an electrical signal in a radio communication band, an information signal source, electro-optic modulators driven directly at an input electrical port by said information signal and said LO signal to modulate a portion of said optical carrier signal to form a modulated portion being an optical band information signal for transmission over an optical link; and a photodetector remote from said electro-optic modulators for receiving said transmitted optical band information signal from said optical link, and directly generating an electrical signal that is up-converted for radio transmission, or down-converted to a baseband frequency.

Abstract: A method for predistortion including receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system, generating a pre-distorted multiple-input signal from the received multiple-input signal, generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter, estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments including nonlinear crosstalk between distinct ones of the plurality of input signals; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments.

Abstract: A method for predistortion comprising receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system, generating a pre-distorted multiple-input signal from the received multiple-input signal, generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter, estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments comprising nonlinear crosstalk between distinct ones of the plurality of input signals; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments.

Abstract: An amplifier comprising a main branch amplifier and an auxiliary branch amplifier, wherein one branch is a constant current-biased branch, and another branch is a voltage biased branch, with the branches connected in cascode configuration to form a load modulated amplifier.

Abstract: A concurrent multi-band linearized transmitter (CMLT) has a concurrent digital multi-band predistortion block (CDMPB) and a concurrent multi-band transmitter (CMT) connected to the CDMPB. The CDMPB can have a plurality of digital baseband signal predistorter blocks (DBSPBs), an analyzing and modeling (A&M) stage, and a signal observation feedback loop. Each DBSPB can have a plurality of inputs, each corresponding to a single frequency band of the multi-band input signal, and its output corresponding to a single frequency band; each output connect corresponding to an input of the CMLT. The A&M stage can have a plurality of outputs connected to and updating the parameters of the DBSPBs, and a plurality of inputs connected to either both outputs of the signal observation loop or the output of the subsampling loop and to outputs of the DBSPBs. The A&M stage can perform signals' time alignment, reconstruction of signals and compute parameters of DBSPBs.

Abstract: A method for predistortion comprising receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system, generating a pre-distorted multiple-input signal from the received multiple-input signal, generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter, estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments comprising nonlinear crosstalk between distinct ones of the plurality of input signals; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments.

Abstract: A radio communication system comprising an optical carrier generator for generating at least a pair of frequency spaced optical carrier signals, a transceiver configured to modulate a first portion of the pair of spaced optical carrier signals with downlink (DL) information to generate a modulated first optical signal, combine an unmodulated second optical signal formed of a remaining unmodulated second portion of the pair of spaced optical carrier signals with the modulated first optical signal to form a combined optical signal for transmission over an optical link, receive an optical uplink (UL) signal from said optical link, said optical UL signal comprising UL information modulated on said unmodulated second portion of the spaced optical carrier signals and down convert said received optical UL signal using a photodetector to output an electrical signal at a baseband frequency.

Abstract: An amplifier comprising a current-biased active device, a voltage-biased active device, the voltage-biased active device and the current-biased active device are connected in series, to form a cascade of active devices, and an input terminal and an output terminal, the cascade of active devices connected between the input terminal and the output terminal, having an output terminal for driving a load impedance with an output signal in response to an input signal applied to the input terminal.

Abstract: A radio communication system comprising an optical carrier generator for generating at least a pair of frequency spaced optical carrier signals, a transceiver configured to modulate a first portion of the pair of spaced optical carrier signals with downlink (DL) information to generate a modulated first optical signal, combine an unmodulated second optical signal formed of a remaining unmodulated second portion of the pair of spaced optical carrier signals with the modulated first optical signal to form a combined optical signal for transmission over an optical link, receive an optical uplink (UL) signal from said optical link, said optical UL signal comprising UL information modulated on said unmodulated second portion of the spaced optical carrier signals and down convert said received optical UL signal using a photodetector to output an electrical signal at a baseband frequency.

Abstract: A concurrent multi-band linearized transmitter (CMLT) has a concurrent d a multi-band predistortion block (CDMPB) and a concurrent multi-band transmitter (CMT) connected to the CDMPB, The CDMPB can have a plurality of digital baseband signal predistorter blocks (DBSPBs), an analyzing and modeling (A&M) stage, and a signal observation feedback loop. Each DBSPB can have a plurality of inputs, each corresponding to a single frequency band of the multi-band input signal, and its output corresponding to a single frequency band; each output connect corresponding to an input of the CMLT. The A&M stage can have a plurality of outputs connected to and updating the parameters of the DBSPBs, and a plurality of inputs connected to either both outputs of the signal observation loop or the output of the subsampling loop and to outputs of the DBSPBs. The A&M stage can perform signals' time alignment, reconstruction of signals and compute parameters of DBSPBs.

Abstract: A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

Abstract: A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

Abstract: A method for predistortion comprising receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system, generating a pre-distorted multiple-input signal from the received multiple-input signal, generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter, estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments comprising nonlinear crosstalk between distinct ones of the plurality of input signals; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments.

Abstract: The present invention relates to a method for multiple-input multiple-output impairment pre-compensation comprising: receiving a multiple-input signal; generating a pre-distorted multiple-input signal from the received multiple-input signal; generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter; estimating impairments generated by the multiple-input and multiple-output transmitter; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments. The present invention also relates to a pre-compensator for use with a multiple-input and multiple-output transmitter, comprising: a multiple-input for receiving a multiple-input signal; a matrix of pre-processing cells for generating a pre-distorted multiple-input signal from the received multiple-input signal; and a multiple-output for feeding the pre-distorted multiple-input signal to the multiple-input and multiple-output transmitter.

Abstract: A receiver comprising a signal phase shifting block generating concurrent phase shifted copies of an input signal, and an impedance translation function block configured to receive the phase shifted copies of the input signal and generate a down converted signal wherein the impedance translation function block is driven by a single clock signal of frequency determined by a desired carrier frequency. The receiver including an energy harvesting block coupled to the phase shifting block to receive one or more in-band or out-of-band interferers in the input signal and reflected signals from the impedance translation function block due to nonlinearities.

Abstract: A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

Abstract: A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.