Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Cancelling of intermodulation interference is described. A digital signal sample (x) is received and a power of the received digital signal sample is obtained (243). Based on the obtained power, at least one model value is obtained from a model (244) 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 (245) 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for determining a centre 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 centre frequency for a downlink communication channel in the unlicensed frequency band.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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

Abstract: 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.

Abstract: Cancelling of intermodulation interference is described. A digital signal sample (x) is received and a power of the received digital signal sample is obtained (243). Based on the obtained power, at least one model value is obtained from a model (244) 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 (245) 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.