Abstract: It is provided a method for reducing interference. The method is performed in a receiver and comprises the steps of: receiving a first signal forming part of a symbol; extracting a differential signal by comparing the first signal with a second signal, wherein the first signal and the second signal are based on the same information; estimating a base frequency of the differential signal for the symbol; mapping the base frequency to a first time of the symbol; estimating frequencies at other times of the symbol using interpolation and/or extrapolation using base frequencies from at least one adjacent symbol; reconstructing an interfering signal based on the estimated frequencies; and subtracting the reconstructed interfering signal from a received signal for the symbol.

Abstract: It is presented a method for determining a position of a wireless device, the method being performed in a network node connected to a plurality of remote radio head devices each comprising a first antenna device which can be used for a first MIMO, multiple input multiple output, stream and a second antenna device which can be used for a second MIMO stream. The method comprises the steps of: sending a first cell identifier for transmission on both the first antenna device and the second antenna device of each one of the remote radio head devices; sending a second cell identifier, for transmission on an antenna device of only a specific remote radio head device; receiving a measurement report from the wireless device associated with the second cell identifier; and determining a position of the wireless device based on the received measurement report.

Abstract: It is provided a method for reducing bit rate requirement over an uplink fronthaul link. The method is performed in a fronthaul transmitter of a radio network node and comprises the steps of: determining a group of frequency-domain resource elements having been received over a wireless channel (40); estimating channel information (42); reducing a number of bits for representing the respective frequency-domain resource element, to thereby obtain a modified resource element (44); transmitting the modified resource elements of the group over the fronthaul link to a fronthaul receiver (46); and transmitting compression metadata (48), indicating how the reduction was performed, over the fronthaul link to the fronthaul receiver which performs the steps of receiving the modified resource elements (50), receiving the compression metadata (52) and expanding the resource elements to increase the number of bits for representing the frequency-domain resource elements (54).

Abstract: It is provided a splitter device comprising: a first trunk cable interface for connecting with a first aggregation node via a first trunk cable; a first radio head interface for connecting to a first remote radio head via a first distribution cable; a second radio head interface for connecting to a second remote radio head via a second distribution cable; a signal combiner and splitter connected to the first radio head interface and the second radio head interface; and a radio signal refresh unit provided between the first trunk cable interface and the signal combiner and splitter. The radio head interfaces comprise respective gain control units and uplink signal amplifiers, wherein a gain of the uplink signal amplifiers is adjusted based on a signal from the respective gain control unit.

Abstract: It is provided a method for reducing interference. The method is performed in a receiver and comprises the steps of: receiving a first signal forming part of a symbol; extracting a differential signal by comparing the first signal with a second signal, wherein the first signal and the second signal are based on the same information; estimating a base frequency of the differential signal for the symbol; mapping the base frequency to a first time of the symbol; estimating frequencies at other times of the symbol using interpolation and/or extrapolation using base frequencies from at least one adjacent symbol; reconstructing an interfering signal based on the estimated frequencies; and subtracting the reconstructed interfering signal from a received signal for the symbol.

Abstract: A central node for digital subscriber line access multiplex.

Abstract: A method (100, 200) in a synchronization control unit is disclosed. The method enables synchronization of a plurality of distributed devices with a network and comprises the steps of receiving a wireless synchronization signal from a network node over a wireless channel (104, 204) and processing the received synchronization signal (108, 208). The method further comprises transmitting the processed synchronization signal to the plurality of distributed devices over a local connection which is different to the wireless channel over which the wireless synchronization channel is received (120, 220). Also disclosed are a synchronization control unit (300, 400) and a computer program product.

Abstract: It is presented a hybrid coil circuit comprising: a transformer; a common mode choke, wherein all choke windings are magnetically coupled; an impedance matching device connected on a middle choke winding, the impedance matching device being connected to ground; a first port being provided between a first choke winding and the impedance matching device; a second port being provided between a third choke winding and the impedance matching device; a third port being provided between either end of a second transformer winding; a first inductor arranged between the impedance matching device and the first port; and a second inductor arranged between the impedance matching device and the second port, wherein the first inductor and the second inductor are magnetically coupled.

Abstract: A first network node of a cellular system is configured for communication with a second network node over a twisted pair wire. The first network node includes a receiver for receiving, over the twisted pair wire, an intermediate frequency signal from the second network node, which intermediate frequency signal has been converted from a high frequency signal having a frequency higher than the frequency of the intermediate frequency signal by the second network node, and a down-converter for converting the intermediate frequency signal to a low frequency signal having a frequency lower than the frequency of the intermediate frequency signal. The first network node also includes an up-converter for converting a received low frequency signal to an intermediate frequency signal having a frequency higher than the frequency of the low frequency signal.

Abstract: Vector Control Entity and method therein for Disorderly Leaving Events, DLEs, causing Sudden Termination Change in a DSL system. The method comprises, when a DLE occurs on a line m in a vectored group of DSL lines, and the transmission on line m is, at least partly, continued: obtaining at least one error sample from CPEs connected to other lines in the vectored group of DSL lines, and calculating an estimate of the channel coefficients, H?, changed due to the DLE. The estimate is calculated based on the at least one error sample, and thus a channel estimate is provided. The method further comprises modifying a downstream precoder, based on the channel estimate, such that retraining of the other lines in the vectored group due to the DLE is avoided. The estimate of the channel coefficients is calculated based on the model H?=H+C?H.

Abstract: Disclosed is a method for mitigating crosstalk performed by a network node of a wireless communication network operable in a base station system of the wireless communication network, the base station system comprising an intermediate radio unit, IRU, a baseband unit, BBU, connected to the IRU and a plurality of radio heads, RHs, connected to the IRU via a plurality of metallic conductors.

Abstract: It is presented a method for testing a cable connectable to a remote radio head. The method is performed in a test device and comprises the steps of: generating an outbound test container, the outbound test container comprising digital samples representing a test signal; transmitting the outbound test container and a frequency parameter indicating a frequency on which the test signal is to be transmitted to a converter device being connectable to a plurality of remote radio heads via respective cables, for transmission by the converter device; receiving an inbound test container, the inbound test container comprising digital samples of a response signal received by the converter device based on the outbound test container; and evaluating the inbound test container.

Abstract: It is provided a splitter device comprising: a first trunk cable interface for connecting with a first aggregation node via a first trunk cable; a first radio head interface for connecting to a first remote radio head via a first distribution cable; a second radio head interface for connecting to a second remote radio head via a second distribution cable; a signal combiner and splitter connected to the first radio head interface and the second radio head interface; and a radio signal refresh unit provided between the first trunk cable interface and the signal combiner and splitter. The radio head interfaces comprise respective gain control units and uplink signal amplifiers, wherein a gain of the uplink signal amplifiers is adjusted based on a signal from the respective gain control unit.

Abstract: Systems and methods for determining non-linear precoding coefficients are disclosed. In some embodiments, a method of determining non-linear precoding coefficients for transmitting at least one frequency tone on lines includes obtaining a channel matrix that relates an input of the lines to an output of the lines for the at least one frequency tone. The method also includes computing a metric for each line in a subset of the lines and determining a line order for the subset of the lines based on the metric for each line in the subset of the lines. The method also includes reordering elements of the channel matrix based on the line order for the subset of the lines to create a reordered channel matrix and determining the non-linear precoding coefficients based on the reordered channel matrix. This may provide a systematic way to sort lines and balance the bit rates between different lines.

Abstract: A device for limiting crosstalk between vectoring modems connected to a group of communication lines comprises a subgroup determining element that obtains information of the division into subgroups, each subgroup being made up of lines experiencing cross-talk from each other, and assigns operational pilot sequences to the group according to the division, an operational sequence transmission control element that transmits the operational sequences on the lines to the modems, which sequences are mutually orthogonal to each other and each communication line receives a corresponding sequence, and a corrective action determining element that obtains cross-talk measurements related to the transmitted operational pilot sequences and determines, for each subgroup, cross-talk and corrective action based on measurements made for a number of sequence symbols, which number corresponds to the minimum number required for obtaining mutually orthogonal pilot sequences within the subgroup.

Abstract: There is provided spectrum shaping of a signal. A frequency-domain representation of the signal to be spectrum-shaped is provided. The signal is associated with a set of constellation points having a minimum distance. A spectrum-shaped signal is determined by altering a proper subset of the constellation points while maintaining the minimum distance between all of the constellation points. The spectrum-shaped signal is transformed into a time-domain signal.

Abstract: Vector Control Entity and method therein for Disorderly Leaving Events, DLEs, causing Sudden Termination Change in a DSL system. The method comprises, when a DLE occurs on a line m in a vectored group of DSL lines, and the transmission on line m is, at least partly, continued: obtaining at least one error sample from CPEs connected to other lines in the vectored group of DSL lines, and calculating an estimate of the channel coefficients, H?, changed due to the DLE. The estimate is calculated based on the at least one error sample, and thus a channel estimate is provided. The method further comprises modifying a downstream precoder, based on the channel estimate, such that retraining of the other lines in the vectored group due to the DLE is avoided. The estimate of the channel coefficients is calculated based on the model H?=H+C?H.

Abstract: A method (100, 200) in a synchronisation control unit is disclosed. The method enables synchronisation of a plurality of distributed devices with a network and comprises the steps of receiving a wireless synchronisation signal from a network node over a wireless channel (104, 204) and processing the received synchronisation signal (108, 208). The method further comprises transmitting the processed synchronisation signal to the plurality of distributed devices over a local connection which is different to the wireless channel over which the wireless synchronisation channel is received (120, 220). Also disclosed are a synchronisation control unit (300, 400) and a computer program product.

Abstract: Disclosed is a method performed by a base station system of a wireless communication network, for increasing signal quality of signals sent from a radio head (RH) to a radio unit (RU) over a metallic conductor. The base station system comprising a baseband unit (BBU), the RU and the RH and the RU is connected to the RH via the metallic conductor. The method comprises, at the RH: amplifying, by an amplification unit, a signal to be transmitted from the RH to the RU; changing the signal amplification level of the amplification unit; and transmitting the amplified signal to the RU. The method further comprises, at the RU: receiving the amplified signal and compensating, by a compensating unit capable of adapting its amplification level, for the change in signal amplification level performed at the RH such that the strength of the signal is transparent to the base station system.

Abstract: It is presented a method for assisting the determining of a position of a wireless device, the method being performed in a network node connected to a plurality of remote radio head devices via a combiner. The method comprises the steps of: receiving an uplink signal via the combiner; comparing a carrier frequency of the uplink signal with a set of manipulation schemes for a carrier frequency of uplink signals, wherein the manipulation schemes are different for at least some of the plurality of remote radio head devices; and providing a proximity indication that the position of the wireless device is in the vicinity of a remote radio head device the frequency manipulation scheme of which best matches the uplink signal. A corresponding network node, computer program, and computer program product are also presented.