Abstract: Apparatus, including a communication device which has two or more radio frequency (RF) ports for communicating in respective frequency bands. The apparatus also includes a substrate which has two or more interconnection ports, and which are respectively connected to the two or more RF ports of the communication device and are configured to couple a selected one of the RF ports to a duplexer operating at one of the respective frequency bands.

Abstract: A transmitter includes an up-converter and a modular receptacle. The up-converter is coupled to convert an input signal into a Radio Frequency (RF) signal having an output frequency, and is configurable to adjust the output frequency over a frequency range containing multiple sub-bands. The modular receptacle includes a first interconnection adapter coupled to the up-converter and a second interconnection adapter for coupling to an antenna. The receptacle is configured to receive between the first and second interconnection adapters a Power Amplifier (PA), which is selected from a group of power amplifiers each covering a respective sub-band in the frequency range.

Abstract: A frequency conversion system includes a mixer, which is coupled to mix an input signal with a Local Oscillator (LO) signal, so as to produce an output signal. Control circuitry is configured to adjust an actual level of the LO signal provided to the mixer, so as to maintain the actual level substantially constant. A nulling signal generator is coupled to inject a nulling signal into the input signal prior to mixing with the LO signal adjusted by the control circuitry.

Abstract: A method for communication includes receiving a signal, which carries data bits and is distorted by multiple impairments including one or more frequency offsets and one or more In-phase/Quadrature (I/Q) imbalances. A corrected signal is produced by applying to the received signal a sequence of corrections to compensate for the impairments. The sequence includes a first and a third correction of one correction type and a second correction of another correction type intervening between the first and third corrections in the sequence, the correction types consisting of frequency offset corrections and I/Q imbalance corrections. The data bits are extracted from the corrected signal.

Abstract: A communication terminal includes first and second transmitters, which are coupled to produce respective first and second Radio Frequency (RF) signals that are phase-shifted with respect to one another by a beamforming phase offset, and to transmit the RF signals toward a remote communication terminal. The terminal includes a reception subsystem including first and second receivers and a phase correction unit. The first and second receivers are respectively coupled to receive third and fourth RF signals from the remote communication terminal. The phase correction unit is coupled to produce, responsively to the third and fourth RF signals, a phase correction for correcting an error component in the beamforming phase offset.

Abstract: A method for power measurement includes applying a nonlinear function to a Radio Frequency (RF) signal that includes a modulated component and a spurious component, so as to produce a broadband signal that includes a Direct-Current (DC) component, a baseband component and one or more High-Frequency (HF) components. The broadband signal is Band-Pass (BP) filtered so as to produce a bandpass signal from which the DC and HF components are removed. Based on the bandpass signal, a power of the modulated component in the RF signal is estimated irrespective of the spurious component.

Abstract: A communication apparatus includes transmission circuitry and a frequency conversion unit. The transmission circuitry is configured to down-convert an input Intermediate Frequency (IF) signal using a transmit (TX) Local Oscillator (LO) signal so as to produce a TX baseband signal, to up-convert the TX baseband signal to produce an output Radio Frequency (RF) signal, and to send the output RF signal to an antenna. The frequency correction unit is configured to estimate a frequency of the TX baseband signal or of the input IF signal, and to adjust the TX LO signal based on the estimated frequency so as to cause the transmission circuitry to down-convert the input IF signal to a predefined target frequency.

Abstract: A method includes amplifying a non-constant-envelope input signal using a main amplifier having a first gain that varies depending on a supply voltage of the main amplifier. A constant-envelope signal is amplified using a reference amplifier having a second gain that varies depending on the supply voltage of the reference amplifier. Both the main amplifier and the reference amplifier are operated using a same variable supply voltage whose amplitude varies over time. A gain control signal is produced so as to compensate for changes in the second gain of the reference amplifier that are caused by the variable supply voltage. The gain control signal is applied in compensating for variations in the first gain of the main amplifier.

Abstract: A communication apparatus includes transmission circuitry and a frequency conversion unit. The transmission circuitry is configured to down-convert an input Intermediate Frequency (IF) signal using a transmit (TX) Local Oscillator (LO) signal so as to produce a TX baseband signal, to up-convert the TX baseband signal to produce an output Radio Frequency (RF) signal, and to send the output RF signal to an antenna. The frequency correction unit is configured to estimate a frequency of the TX baseband signal or of the input IF signal, and to adjust the TX LO signal based on the estimated frequency so as to cause the transmission circuitry to down-convert the input IF signal to a predefined target frequency.

Abstract: A method for communication includes transmitting data from a transmitter to a receiver using Adaptive Coding and Modulation (ACM). The data rate is set by selecting, based on feedback, an ACM profile defining a Forward Error Correction code and a modulation scheme. Upon detecting that the feedback is unusable, an operation of the transmitter is changed independently of the feedback. In another method, data is exchanged over two opposite directions of a bidirectional link that uses ACM by communicating using two ACM profiles. A joint constraint is defined on the two directions. The two ACM profiles are set based on first and second measured reception quality metrics of the two link directions, to meet the joint constraint. In yet another method, a subset of the ACM profiles is temporarily disabled, and the data is transmitted using only the ACM profiles that are not disabled.

Abstract: A method for communication includes transmitting data from a transmitter to a receiver using Adaptive Coding and Modulation (ACM). The data rate is set by selecting, based on feedback, an ACM profile defining a Forward Error Correction code and a modulation scheme. Upon detecting that the feedback is unusable, an operation of the transmitter is changed independently of the feedback. In another method, data is exchanged over two opposite directions of a bidirectional link that uses ACM by communicating using two ACM profiles. A joint constraint is defined on the two directions. The two ACM profiles are set based on first and second measured reception quality metrics of the two link directions, to meet the joint constraint. In yet another method, a subset of the ACM profiles is temporarily disabled, and the data is transmitted using only the ACM profiles that are not disabled.

Abstract: A method for power measurement includes applying a nonlinear function to a Radio Frequency (RF) signal that includes a modulated component and a spurious component, so as to produce a broadband signal that includes a Direct-Current (DC) component, a baseband component and one or more High-Frequency (HF) components. The broadband signal is Band-Pass (BP) filtered so as to produce a bandpass signal from which the DC and HF components are removed. Based on the bandpass signal, a power of the modulated component in the RF signal is estimated irrespective of the spurious component.

Abstract: Apparatus, including a communication device which has two or more radio frequency (RF) ports for communicating in respective frequency bands. The apparatus also includes a substrate which has two or more interconnection ports, and which are respectively connected to the two or more RF ports of the communication device and are configured to couple a selected one of the RF ports to a duplexer operating at one of the respective frequency bands.

Abstract: A communication receiver includes a front end, which is arranged to receive a Radio Frequency (RF) signal, which includes modulated symbols carrying data that have been encoded by a block Forward Error Correction (FEC) code. The front end converts the RF signal to a sequence of soft received symbols, wherein the soft received symbols are subject to distortion by at least first and second noise components having respective at least first and second statistical distributions. A metric calculation unit is arranged to process the soft received symbols so as to extract parameters indicative of the at least first and second statistical distributions, and to compute FEC metrics based on the extracted parameters. A FEC decoder is arranged to accept the FEC metrics as input, and to process the metrics in an iterative FEC decoding process so as to decode the FEC code and reconstruct the data.

Abstract: A communication system includes first and second transmitters, which are coupled to transmit respective first and second Radio Frequency (RF) signals carrying first and second data over a wireless communication channel. The transmitters are coupled to select an operational mode from a group of operational modes and to operate in the selected operational mode. The group of the operational modes includes at least two of a protection mode, wherein the second transmitter serves as backup to the first transmitter, a spatial multiplexing mode, in which the first data is different from the second data and the first and second transmitters transmit simultaneously, and a beam-forming mode, in which the first data is identical to the second data, the second RE signal includes a phase-shifted replica of the first RE signal, and the first and second transmitters transmit simultaneously.

Abstract: A communication terminal includes first and second transmitters, which are coupled to produce respective first and second Radio Frequency (RF) signals that are phase-shifted with respect to one another by a beamforming phase offset, and to transmit the RF signals toward a remote communication terminal. The terminal includes a reception subsystem including first and second receivers and a phase correction unit. The first and second receivers are respectively coupled to receive third and fourth RF signals from the remote communication terminal. The phase correction unit is coupled to produce, responsively to the third and fourth RF signals, a phase correction for correcting an error component in the beamforming phase offset.

Abstract: A communication apparatus includes transmission circuitry and a frequency conversion unit. The transmission circuitry is configured to down-convert an input Intermediate Frequency (IF) signal using a transmit (TX) Local Oscillator (LO) signal so as to produce a TX baseband signal, to up-convert the TX baseband signal to produce an output Radio Frequency (RF) signal, and to send the output RF signal to an antenna. The frequency correction unit is configured to estimate a frequency of the TX baseband signal or of the input IF signal, and to adjust the TX LO signal based on the estimated frequency so as to cause the transmission circuitry to down-convert the input IF signal to a predefined target frequency.

Abstract: A transmitter includes an Outdoor Unit (ODU) including circuitry, and an Indoor Unit (IDU) that is configured to predistort a signal based on a non-linearity model of the circuitry having one or more model parameters, and to forward the predistorted signal to the ODU. The ODU is configured to accept the predistorted signal from the IDU, to amplify and transmit the predistorted signal using the circuitry, to estimate the non linearity model parameters, and to send the estimated model parameters to the IDU so as to cause the IDU to apply the model parameters in predistoring the signal.

Abstract: A method includes amplifying a non-constant-envelope input signal using a main amplifier having a first gain that varies depending on a supply voltage of the main amplifier. A constant-envelope signal is amplified using a reference amplifier having a second gain that varies depending on the supply voltage of the reference amplifier. Both the main amplifier and the reference amplifier are operated using a same variable supply voltage whose amplitude varies over time. A gain control signal is produced so as to compensate for changes in the second gain of the reference amplifier that are caused by the variable supply voltage. The gain control signal is applied in compensating for variations in the first gain of the main amplifier.

Abstract: A communication terminal includes first and second transmitters, which are coupled to produce respective first and second Radio Frequency (RF) signals that are phase-shifted with respect to one another by a beamforming phase offset, and to transmit the RF signals toward a remote communication terminal. The terminal includes a reception subsystem including first and second receivers and a phase correction unit. The first and second receivers are respectively coupled to receive third and fourth RF signals from the remote communication terminal. The phase correction unit is coupled to produce, responsively to the third and fourth RF signals, a phase correction for correcting an error component in the beamforming phase offset.