Telefonaktiebolaget Lm Ericsson (publ)

Guangdong Oppo Mobile Telecommunications Corp., Ltd.

Youping Su

Li Wang

Qingyu Miao

Chunhui Zhang

Huaisong Zhu

Yuanjun Xu

Iana Siomina

Zhiheng Guo

Shuhui Chen

Jacob Österling

Fredrik Huss

Mats Klingberg

Alireza Nejatian

Jichang Liao

Min Wei

Shan Lu

Gerlach Spee

Alireza Najatian

Yong Shen

Björk Vimar

Lei Ziao

Zhongwen Li

Jia Chen

Ming Li

Vimar Bjoerk

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.

Radio unit for unsynchronized TDD multi-band operation

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. The method then comprises transmitting LTE or NR signals only in a first group of the scheduled LTE PRBs that experience an interference from the at least one NB-IoT PRB that is lower than the interference experienced from the at least one NB-IoT PRB by a second group of the LTE PRBs, or transmitting LTE or NR signals modulated with a first modulation scheme in the LTE PRBs of the first group, and transmitting LTE or NR signals modulated with a second modulation scheme more robust than the first modulation scheme in the LTE PRBs of the second group.

Method and network node for handling transmission of LTE or NR signals and NB-IoT signals to wireless communication devices

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.

Method and active antenna system in telecommunication networks

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.

Method and entity in TDD radio communications

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.

Method and radio network node for compensation for local oscillator pulling or pushing

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&#x2212;, and a second Q component, Qin&#x2212;, wherein phases of Qin+, Iin&#x2212; and Qin&#x2212; are respectively offset with respect to phases of Iin+, Qin+ and Iin&#x2212; by &#x3c0;/2. Then, the four sampled signals are filtered through the use of polyphase filters to obtain a first set of filtered signals (a, a, a, a) each of which has a same power as the first frequency band component and a second set of filtered signals (b, b, b, b) each of which has a same power as the second frequency band component. Subsequently, a power of the first frequency band component, a power of the second frequency band component and a total power of the first frequency band component and the second frequency band component are estimated, based on the four sampled signals, the first set of filtered signals and the second set of filtered signals. Next, the first frequency band component and the second frequency band component are selectively attenuated based on the estimated powers.

Method and dual band radio receiver for handling analog dual band radio signal

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.

Homodyne receiver calibration

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.

Method and apparatus for common observation receiver for transmitter and receiver

Method and transceiver arrangements for reducing a leakage signal's impact on a receiver partof the transceiver arrangement. The leakage signal originates from a transmitter partof the transceiver arrangement. The radio base station is adapted to communicate in a Time Division Duplex, TDD mode in a cellular network. The method comprises frequency shifting, by the transmitter part, a downlink, DL, baseband by an offset frequency, f, the DL baseband comprising DL data. Furthermore, the method comprises to mixing, by the transmitter part (), the frequency shifted DL baseband with a Transmitter Local Oscillator, TX LO, frequency, fto produce a DL signal spectrum. The offset frequency, f, and the TX LO frequency fis selected such that f=f&#x2212;f, or f=f+fwhere fis the center frequency of the DL signal spectrum, such that the TX LO leakage signal reachingthe receiver partis located outside, or on an edge of a UL signal spectrum when received by the receiver part. By frequency shifting an output frequency of a transmitter local oscillator with an offset frequency, and frequency shifting a transmitter baseband with the offset frequency, but in a reverse direction, leakage signals originating from the transmitter local oscillator may be prevented from affecting a receiver RF spectrum, without affecting the transmitter RF spectrum.

Method and apparatus for preventing transmitter leakage

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.

Method and apparatus for facilitating antenna calibration and transceiver

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, f, is selected based on a frequency fof the lower frequency band, and a frequency fof 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 f. The LO frequency fis selected to satisfy f&#x3c;f&#x3c;f, where fand fare any frequency of the lower or higher frequency band, respectively.

Method and arrangements in multi-band receivers

Method and multi carrier receiver for removing interference from a RF-signal. In a multi carrier receiver with a heterodyne receiver structure, the RF-signal is received from a multi carrier transmitting entity. The RF-signal comprises a data part an interference part. The interference part is detected by means of the interference unit, and a frequency and a power level of the interference part is determined. A frequency of a first LO is adjusted, such that an output signal of a first mixer is frequency shifted towards an upper edge or a lower edge of a first IF bandpass filter when the determined power level exceeds a predetermined threshold. By detecting an interference part of an incoming RF-signal and controlling a local oscillator based on the detected interference, an effective and flexible solution is achieved for removing interference from the RF-signal.

Method and apparatus relating to reception of radio signals

Method and apparatus for antenna calibration have been disclosed. A radio unit () is provided. The radio unit () may comprise: a plurality of transmit/receive (TX/RX) paths; a plurality of radio frequency (RF) ports () connected with the plurality of TX/RX paths; and a coupling unit (), coupled with the plurality of TX/RX paths and configured to inject an uplink (UL) calibration signal () into at least one of the plurality of TX/RX paths and extract a downlink (DL) calibration signal () from at least one of the plurality of TX/RX paths. A normal TX/RX path may be reused both for antenna calibration and antenna supervision. Thus, a low cost hardware solution for antenna calibration is provided. An AIR base station () comprising such radio unit () is also provided.

Method and apparatus for antenna calibration

The present disclosure provides an apparatus and a method for canceling inter-modulation (IM) products in a transceiver. The apparatus includes: a pre-distortion circuit configured to estimate a first IM product caused by a transmission signal and pre-distort the transmission signal to cancel the first IM product; an IM product calculator configured to calculate a second IM product caused by the transmission signal in a received signal based on the first IM product; and a subtractor configured to subtract the second IM product from the received signal.

Apparatus and method for canceling inter-modulation products

The present invention relates to a method for controlling performance in a radio base station communicating in a Time Division Duplex (TDD) mode in a cellular network. The radio base station has a transceiver comprising a transmitter part, a receiver part, and an antenna, the antenna being alternately connectable to the transmitter part and the receiver part. The method comprises: estimating, at the receiver part, a leakage signal in the receiver part, the leakage signal originating from a local oscillator of the transmitter part; and removing, at the receiver part, the estimated leakage signal from a received uplink signal. The present invention also relates to a corresponding radio base station.

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Täby, Sweden

Youping Su