Abstract: A radio unit for unsynchronized Time Division Duplex (TDD) multi-band operation in a wireless communication system. The radio unit comprises a first resonator arrangement comprising one or more resonators tuned for operating at a first frequency band. A first terminal of the first resonator arrangement is coupled to an antenna element. The radio unit further comprises a second resonator arrangement comprising one or more resonators tuned for operating at a second frequency band. A first terminal of the second resonator arrangement is coupled to the antenna element. The radio unit further comprises a tunable resonator arrangement comprising at least four tunable resonators. The at least four tunable resonators in the tunable resonator arrangement are tuned according to different operating modes.

Abstract: Disclosed is a method performed by a radio access network node of a wireless communication network for handling transmission of LTE or NR signals as well as NB-IoT signals to wireless communication devices over a carrier comprising a plurality of PRBs. The method comprises scheduling the carrier so that at least one of the PRBs is to be used for transmission of NB-IoT signals, called NB-IoT PRBs, and some of the PRBs are to be used for transmission of LTE or NR signals, called LTE PRBs.

Abstract: A multi-band radio, comprising a first antenna; a second antenna that is physically separate from the first antenna; one or more transmitters configured to: transmit a first transmit signal in a first transmit frequency band via the first antenna; and transmit a second transmit signal in a second transmit frequency band via the first antenna; and one or more receivers configured to: receive a first receive signal in a first receive frequency band via the second antenna; and receive a second receive signal in a second receive frequency band via the second antenna.

Abstract: A method for calibrating an active antenna system (AAS). The AAS comprises a radio unit and an antenna array. The radio unit comprises a plurality of transceiver branches. The method comprises calibrating at least one, but less then all, out of the plurality of transceiver branches as reference branch or branches. The method further comprises calibrating non-calibrated transceiver branch or branches out of the plurality of transceiver branches while the antenna array and the radio unit are connected. The disclosure further relates to a method for onsite automatic maintenance of an active antenna system, and to an active antenna system.

Abstract: A radio unit for unsynchronized Time Division Duplex (TDD) multi-band operation in a wireless communication system. The radio unit comprises a first resonator arrangement comprising one or more resonators tuned for operating at a first frequency band. A first terminal of the first resonator arrangement is coupled to an antenna element. The radio unit further comprises a second resonator arrangement comprising one or more resonators tuned for operating at a second frequency band. A first terminal of the second resonator arrangement is coupled to the antenna element. The radio unit further comprises a tunable resonator arrangement comprising at least four tunable resonators. The at least four tunable resonators in the tunable resonator arrangement are tuned according to different operating modes.

Abstract: A method for performing transmission and reception of signals in a radio transceiver arrangement includes creating a first analogue signal to be transmitted based on a digitally predistorted digital input signal and converting a second analogue signal into a digital output signal. The second analogue signal is a combination of a received signal and a transmitter observation signal. The received signal is based on a radio signal received by the radio transceiver arrangement. The transmitter observation signal is based on a tapped signal of the first analogue signal. The digital predistortion of the digital input signal is adapted based on the part of the output digital signal that corresponds to the transmitter observation signal.

Abstract: Disclosed is a method performed by a radio access network node of a wireless communication network for handling transmission of LTE or NR signals as well as NB-IoT signals to wireless communication devices over a carrier comprising a plurality of PRBs. The method comprises scheduling the carrier so that at least one of the PRBs is to be used for transmission of NB-IoT signals, called NB-IoT PRBs, and some of the PRBs are to be used for transmission of LTE or NR signals, called LTE PRBs.

Abstract: A method for calibrating an active antenna system (AAS). The AAS comprises a radio unit and an antenna array. The radio unit comprises a plurality of transceiver branches. The method comprises calibrating at least one, but less then all, out of the plurality of transceiver branches as reference branch or branches. The method further comprises calibrating non-calibrated transceiver branch or branches out of the plurality of transceiver branches while the antenna array and the radio unit are connected. The disclosure further relates to a method for onsite automatic maintenance of an active antenna system, and to an active antenna system.

Abstract: Embodiments provides a radio network entity and the method thereof for improving filtering performance in a time division duplexing radio communication system, the radio network entity comprises: a first filter, which is configured to perform a first type of filtering for a signal to be transmitted to, or received from a device in the radio communication system through a radio interface, with a common filtering requirement for transmitting and receiving fulfilled, a second filter, which is configured to perform a second type of filtering for the signal to be transmitted to the device, with additional filtering requirement for transmitting besides the common filtering requirement fulfilled; and a third filter, which is configured to perform a third type of filtering for the signal received from the device, with additional filtering requirement for receiving besides the common filtering requirement fulfilled.

Abstract: Disclosed is a method and a radio network node for compensating for local oscillator pulling or pushing. The method comprises determining, in a digital domain, a correction phase for the local oscillator to offset a phase error caused by the local oscillator pulling or pushing. The method also comprises correcting a phase of the baseband signal in the digital domain using the correction phase to compensate for the local oscillator pulling or pushing With the proposed method and radio network node, the phase error caused by the local oscillator pulling or pushing could be diminished due to phase correction in the digital domain.

Abstract: Embodiments provides a radio network entity and the method thereof for improving filtering performance in a time division duplexing radio communication system, the radio network entity comprises a first filter which is configured to perform a first type of filtering for a signal to be transmitted to or received from a device in the radio communication system through a radio interface, with a common filtering requirement for transmitting and receiving fulfilled a second filter, which is configured to perform a second type of filtering for the signal to be transmitted to the device, with additional filtering requirement for transmitting besides the common filtering requirement fulfilled and a third filter, which is configured to perform a third type of filtering for the signal received from the device with additional filtering requirement for receiving besides the common filtering requirement fulfilled.

Abstract: The present disclosure provides a method and a dual band receiver for handling an analog dual band radio signal comprising a first frequency band component and a second frequency band component. The method comprises sampling the analog dual band radio signal through the use of interleaving analog-to-digital converters, ADCs, to obtain four sampled signals including a first I component, Iin+, a first Q component, Qin+, a second I component, Iin?, and a second Q component, Qin?, wherein phases of Qin+, Iin? and Qin? are respectively offset with respect to phases of Iin+, Qin+ and Iin? by ?/2. Then, the four sampled signals are filtered through the use of polyphase filters to obtain a first set of filtered signals (a1, a2, a3, a4) each of which has a same power as the first frequency band component and a second set of filtered signals (b1, b2, b3, b4) each of which has a same power as the second frequency band component.

Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: The present disclosure provides a method and a dual band receiver for handling an analog dual band radio signal comprising a first frequency band component and a second frequency band component. The method comprises sampling the analog dual band radio signal through the use of interleaving analog-to-digital converters, ADCs, to obtain four sampled signals including a first I component, Iin+, a first Q component, Qin+, a second I component, Iin?, and a second Q component, Qin?, wherein phases of Qin+, Iin? and Qin? are respectively offset with respect to phases of Iin+, Qin+ and Iin? by ?/2. Then, the four sampled signals are filtered through the use of polyphase filters to obtain a first set of filtered signals (a1, a2, a3, a4) each of which has a same power as the first frequency band component and a second set of filtered signals (b1, b2, b3, b4) each of which has a same power as the second frequency band component.

Abstract: In a method in a common observation receiver of a transceiver, a Transmitter Radio Frequency, TXRF, signal spectrum is received, a Receiver Radio Frequency, RXRF, signal spectrum is further received. Furthermore, a switching scheme is determined based on whether the type of the transmitter and the receiver is Frequency Division Duplex, FDD, or Time Division Duplex, TDD. Based on the switching scheme, the TXRF signal spectrum and the RXRF signal spectrum are switched into a switched baseband signal spectrum. By arranging a common observation receiver in a radio transceiver, and observing radio frequency signal spectrums, the transceiver may acquire knowledge about nonlinearities and other irregularities of applied components.

Abstract: There is disclosed mechanisms for calibrating a homodyne receiver in a signal distribution network for time division duplex; a corresponding method is performed by a baseband calibration module. The method comprises acquiring a transmission signal being input to a homodyne transmitter of the signal distribution network; acquiring, from a heterodyne transmitter observation receiver of the signal distribution network, a first received version of the transmission signal; acquiring, from a homodyne receiver of the signal distribution network, a second received version of the transmission signal; and, calibrating the homodyne receiver using a comparison of the first received version of the transmission signal and the second received version of the transmission signal, using the first received version of the transmission signal as a reference signal, and using the transmission signal as a calibration signal.

Abstract: Method and transceiver arrangements for reducing a leakage signal's impact on a receiver part 320 of the transceiver arrangement 300. The leakage signal originates from a transmitter part 310 of the transceiver arrangement 300. The radio base station is adapted to communicate in a Time Division Duplex, TDD mode in a cellular network. The method comprises frequency shifting 402, by the transmitter part 310, a downlink, DL, baseband by an offset frequency, fc, the DL baseband comprising DL data. Furthermore, the method comprises to mixing 404, by the transmitter part (310), the frequency shifted DL baseband with a Transmitter Local Oscillator, TX LO, frequency, fLO to produce a DL signal spectrum.

Abstract: An apparatus for facilitating antenna calibration comprising: a directional coupler having first, second, third and fourth ports, the first port selectively connected to a radio transmitter or a radio receiver and the second port connected to an antenna; a power combiner/divider having first, second and third ports; the first port of the power combiner/divider selectively connected to a measurement receiver or a measurement transmitter and the second port of the power combiner/divider connected to the third port of the direction coupler; and a magnitude and phase adjustor connected between the fourth port of the directional coupler and the third port of the power combiner/divider. The magnitude and phase adjustor is configured to be tuned such that any signal input to the second port of the directional coupler results in an output smaller than a predetermined threshold at the first port of the power combiner/divider.

Abstract: Disclosed is a method and a radio network node for compensating for local oscillator pulling or pushing. The method comprises determining, in a digital domain, a correction phase for the local oscillator to offset a phase error caused by the local oscillator pulling or pushing. The method also comprises correcting a phase of the baseband signal in the digital domain using the correction phase to compensate for the local oscillator pulling or pushing With the proposed method and radio network node, the phase error caused by the local oscillator pulling or pushing could be diminished due to phase correction in the digital domain.

Abstract: In a method of a heterodyne FDD receiver for enabling reception of a multi-band RXRF signal spectrum, an RXRF signal spectrum is received, which comprises a lower frequency band and a higher frequency band. A Local Oscillator, LO, output frequency, fLO, is selected based on a frequency fA of the lower frequency band, and a frequency fB of the higher frequency band. Moreover, the RXRF signal spectrum is frequency shifted into an RXIF signal spectrum, by mixing the RXRF signal spectrum with the LO output frequency fLO. The LO frequency fLO is selected to satisfy fA<fLO<fB, where fA and fB are any frequency of the lower or higher frequency band, respectively.