Telefonaktiebolaget Lm Ericsson (publ)

Nokia Corporation

Nokia Siemens Networks Oy

Oy L M Ericsson Ab

Kauko Heinikoski

Marko E Leinonen

Samu Saarinen

Marko Johannes Leukkunen

Miia Karjalainen

Juha Ylinen

Jani Suonperä

Risto Lehtinen

Teemu Tolonen

Risto Tapani Martikkala

Murat Emre Ermutlu

Jorma Pallonen

Pekka Adolfsen

A method performed in a radio access node includes the radio access node receiving a data for transmission to a second radio access node over a communication channel having an unlicensed spectrum. The method further includes, in response to receiving the data, the radio access node receiving a channel measurement signal over the communication channel. The method further includes the radio access node performing an N-point Fast Fourier Transform (FFT) on the channel measurement signal to produce a frequency domain signal with N bins. The method further includes the radio access node performing a power measurement on the frequency domain signal. The method further includes the radio access node analyzing the power measurement of the frequency domain signal. The method further includes the radio access node transmitting the data based on the analysis of the power measurement.

Method and network node for FFT based power detection for LBT in LTE LAA

It is presented a method for determining whether to initiate transmission of data on a candidate radio channel during a candidate period. The method is performed in a transceiver device and comprises the steps of: obtaining a first signal metric indicating a signal level of the candidate radio channel; determining that the first signal metric indicates a signal level being greater than a first threshold; obtaining a second signal metric indicating a signal level of at least one adjacent radio channel, being adjacent in frequency to the candidate radio channel; refraining from initiating transmission on the candidate radio channel in the candidate period when the second signal metric indicates a lower signal level than the first signal metric; and initiating transmission of data on the candidate radio channel in the candidate period when the second signal metric indicates a higher signal level than the first signal metric.

Determining whether to transmit data on a candidate radio channel

Cancelling of intermodulation interference is described. A digital signal sample (x) is received and a power of the received digital signal sample is obtained. Based on the obtained power, at least one model value is obtained from a model that models model values of a non-linearity in amplitude and phase of a received signal that passes through passive and active components in the receiver. The model values correspond to a plurality of powers of the received signal. Intermodulation interference is then cancelled by multiplying the received digital signal sample with the obtained at least one model value, thereby obtaining an output digital signal sample (y) from which intermodulation interference, inflicted by the receiver, is cancelled.

Cancelling intermodulation interference

Herein a Radio Access node for multi band communication and a method therein are described. The Radio Access node is configured for communication with at least one wireless device in a first frequency band. The method comprises performing at least one measurement in a second frequency band, by use of a feedback receiver. The at least one measurement is performed in order to detect signals, in the second frequency band, produced by other entities than the Radio Access node. The feedback receiver is also operable to measure signals transmitted by the Radio Access node.

Method and arrangement for multi band communication

A method for determining a center frequency in an unlicensed frequency band to use for downlink communication in a cellular network. The method is performed in a network node and comprises the steps of: performing a coarse pre-scan when the network node is in a transmit time slot, yielding respective coarse measurement of signal levels for a plurality of frequencies in the unlicensed frequency band; performing an accurate measurement when the network node is in a receive time slot, yielding respective accurate measurement of signal levels for a plurality of frequencies in the unlicensed frequency band; and determining at least one frequency to use as a center frequency for a downlink communication channel in the unlicensed frequency band.

Determining a centre frequency in an unlicensed frequency band to use

Embodiments herein relate to a radio arrangement for enabling communication in a wireless communication network, wherein the radio arrangement comprises at least two signal path configurations for transmitting and/or receiving signals to and/or from a radio device in the wireless communication network. The radio arrangement comprises a radio apparatus and an antenna arrangement connected to the radio apparatus. The radio arrangement is configured to obtain, at the radio apparatus, an indication, which indication is indicating a configuration of the antenna arrangement connected to the radio apparatus. The radio arrangement is further configured to select, for communication in the wireless communication network, a signal path configuration at the radio apparatus and/or the antenna arrangement of the at least two signal path configurations based on the obtained indication.

Radio arrangement, radio apparatus, antenna arrangement and methods performed therein

A method and radio node for controlling transmission of radio signals in a transmitter band to avoid or reduce interference in a victim band, the victim band being separate from the transmitter band in frequency domain. The radio node applies Digital Pre-Distortion, DPD, on signals to be transmitted on at least one carrier in the transmitter band, such that Intermodulation Distortion, IMD, components of the signals are pre-distorted asymmetrically relative the at least one carrier to suppress at least one of the IMD components falling within the victim band. The pre-distorted signals are then amplified in a power amplifier and transmitted on the at least one carrier.

Method and radio node for controlling radio transmission

Cancelling of intermodulation interference is described. A digital signal sample (x) is received and a power of the received digital signal sample is obtained (). Based on the obtained power, at least one model value is obtained from a model () that models model values of a non-linearity in amplitude and phase of a received signal that passes through passive and active components in the receiver. The model values correspond to a plurality of powers of the received signal. Intermodulation interference is then cancelled by multiplying () the received digital signal sample with the obtained at least one model value, thereby obtaining an output digital signal sample (y) from which intermodulation interference, inflicted by the receiver, is cancelled.

It is provided a remote radio head configured to provide a radio interface for a network node. The remote radio head comprising an antenna, an analog interface for connecting with the network node, radio frequency (RF) circuitry configured to convert between intermediate frequency signals of the analog interface and RF signals of the antenna, digital circuitry configured to process transmission and/or reception signals, a first analog to digital converter (ADC) connected to the digital circuitry, and a first digital to analog converter (DAC) connected to the digital circuitry. The first ADC, the digital circuitry, and the first DAC are connected between the antenna and the analog interface for receiving or transmitting radio signals. A corresponding method is also presented.

Remote radio head and associated method

Cancelling crosstalk between at least one transmitter chain and a receiver chain in a wireless communication node makes use of a single feedback path from the transmitter chain that is shared between processing of transmit signals (x) in the transmitter chain and reception signals (s) received in the receiver chain. Information in the shared feedback is used in a crosstalk model to cancel crosstalk in the reception signals.

Cancelling crosstalk

Exemplary embodiments of system and method are provided for measuring signal amplitude, phase and/or delay offsets between multiple transmit signals fed through the transmit signal processing chains and wirelessly transmitted over the transceive antennas of separate transceiver modules, wherein transmit signal coupling between the transmit antennas of said transceiver modules' transmit signal processing chains may be used for synchronizing the transmit signals and calibrating their amplitude, phase and/or delay parameters. The exemplary embodiments further provide a front end arrangement of a wireless transceiver device which can comprise at least two independently controllable transceiver modules, each connected to an associated spatial diversity transceive antenna and comprising at least one associated transmit signal processing chain and at least one associated receive signal processing chain coupled to a common baseband processing unit. The exemplary transceiver architecture can be executed on an antenna loop between the transmit signal processing chain of a first transceiver module and the transmit signal processing chain of a second transceiver over the air interface and relies on an adaptive antenna concept which facilitates a wireless transmission of data via a plurality of wireless communication channels utilizing an array of transceive antennas, receiving feedback information via at least one of said communication channels using such antenna loop and modifying a transmission mode based on the received feedback information.

Multi-transceiver architecture for advanced Tx antenna monitoring and calibration in MIMO and smart antenna communication systems

A transmitter, including at least two transmitter units, each transmitter unit being configured to input an instance of a digital transmit signal, to convert the digital transmit signal to an analog radio signal, and to amplify the analog radio signal. The transmitter is configured to determine a timing difference between the amplified signals, and to adjust timing of at least one of the input signals, so that a predetermined criterion is fulfilled.

Transmitter delay and phase adjustment

The invention is related to a device comprising: generating unit configured to generate a feedback signal; setting unit configured to set a predetermined frequency shift to the feedback signal; evaluating unit configured to evaluate distortion caused in a transmission chain on the basis of the frequency shifted feedback signal; adapting unit configured to adapt quadrature modulation pre-distortion algorithms of the transmission chain; wherein the setting unit is further configured to set the frequency of the feedback signal to an original frequency value; wherein the evaluating unit is further configured to evaluate distortion caused in the feedback chain based on the feedback signal having the original frequency; wherein the adapting unit is further configured to adapt quadrature demodulation pre-distortion algorithms of the feedback chain; and wherein the adapting unit is further configured to adapt other pre-distortion algorithms.

Data processing method, transmitter, device, network element and base station

A switch is particularly advantageous for calibration of signal phase between transmitters, and other uses. The switch has a first data input adapted to input a transmit signal from a first transmitter, a first data output, at least one and preferably multiple bidirectional data ports, and a control input adapted to selectively couple in a first case the first data input to one of the bidirectional data ports, and in a second case one of the bidirectional data ports and the first data input to the first data output. By coupling one data port of the switch to a data port of another identical switch, a transmit signal from another transmitter can be ported to the first said switch, and both signals output to a feedback circuit that finds the phase difference and applies it to a new signal input to one of the transmitters. Beamforming and MIMO uses are also detailed.

Phase and power calibration in active antennas

A transmitter compensates for the non-linearities within a transmission chain. The transmitter includes, for instance, a first forming device for forming, on the basis of at least one set of signal properties, at least one state expansion vector comprising quantities characterizing a signal. The transmitter includes a modifier for modifying the signal characterizing quantities of at least one state expansion vector with the at least one time-domain compensation parameter vector and with the at least one frequency-domain compensation parameter vector to form a pre-distorted signal. The transmitter includes a second forming device for forming a feedback signal from an output signal of a transmission chain. The transmitter includes an adapter for adapting at least one time-domain compensation parameter vector for adapting at least one frequency-domain compensation parameter vector based on a residual error between a transmit signal and the feedback signal.

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Oulu, Finland

Kauko Heinikoski