Abstract: There is provided mechanisms for determining a precoder for APs in a cell-free communication system. A method is performed by a controller of the APs. The method comprises obtaining channel estimates of a radio propagation channel between the APs and user equipment served in the cell-free communication system. The method comprises determining a precoder for the APs. The precoder has a ZF precoding factor and a power allocation factor. The ZF precoding factor is determined from the channel estimates. The power allocation factor is determined by maximizing total transmission power for all user symbols to be transmitted to the user equipment, one user symbol per each user equipment. Transmission power of each of the APs is not larger than a power constraint. Transmission power for each of the user equipment is lower bounded by a scaled heuristic value. The method comprises initiating transmission of precoded user symbols from the APs towards the user equipment.

Abstract: A method performed by an IRU of a base station system, the base station system comprising the IRU, a BBU connected to the IRU, and a first RH connected to the IRU via a packet data network. The first RH is arranged for wireless transmission in RF of a plurality of antenna carriers to UEs. The method comprises receiving, from the BBU, a plurality of first digital representations of the plurality of antenna carriers of the first RH, each first digital representation representing one antenna carrier, the plurality of first digital representations being received in a baseband frequency range, frequency multiplexing the plurality of first digital representations of the plurality of antenna carriers into a second digital representation over a first bandwidth, and transmitting the second digital representation to the first RH.

Abstract: Methods, apparatuses and computer programs are disclosed. The method of allocating network resources to a plurality of media flows in a communications network, the method comprising the steps of: determining a media content characteristic for the plurality of media flows; partitioning the plurality of media flows into one or more media flow groups based on the media content characteristic; initiating allocation of a separate network resource pool to the one or more media flow groups to be used by media flows belonging to respective media flow group.

Abstract: A method performed by an IRU of a base station system, the base station system comprising the IRU, a BBU connected to the IRU, and a first RH connected to the IRU via a packet data network. The first RH is arranged for wireless transmission in RF of a plurality of antenna carriers to UEs. The method comprises receiving, from the BBU, a plurality of first digital representations of the plurality of antenna carriers of the first RH, each first digital representation representing one antenna carrier, the plurality of first digital representations being received in a baseband frequency range, frequency multiplexing the plurality of first digital representations of the plurality of antenna carriers into a second digital representation over a first bandwidth, and transmitting the second digital representation to the first RH.

Abstract: Disclosed is a method performed by an IRU (210) of a base station system (200), the base station system comprising the IRU (210), a BBU (230) connected to the IRU (210), and a first RH (221) connected to the IRU (210) via a packet data network (240). The first RH (221) is arranged for wireless transmission in RF of a plurality of antenna carriers to UEs (250). The method comprises receiving, from the BBU (230), a plurality of first digital representations of the plurality of antenna carriers of the first RH (221), each first digital representation representing one antenna carrier, the plurality of first digital representations being received in a baseband frequency range, frequency multiplexing the plurality of first digital representations of the plurality of antenna carriers into a second digital representation over a first bandwidth, and transmitting the second digital representation to the first RH (221).

Abstract: Described is a method performed by an encoder of a base station system of a wireless communication network, for handling a data stream comprising a number of consecutive IQ samples for transmission over a transmission network between a remote unit and a base unit of the base station system. The remote unit is arranged to transmit wireless signals to and receive from mobile stations, each of the number of IQ samples comprising a first number of bits.

Abstract: Described is a method performed by an encoder of a base station system (100) of a wireless communication network, for handling a bit stream for transmission over a transmission link (165) between a remote unit (160) and a base unit (170) of the base station system. The remote unit is arranged to transmit wireless signals to and receive from mobile stations (180). The bit stream comprises a first OFDM symbol and a second OFDM symbol, each OFDM symbol comprising a number of consecutive IQ samples. The method comprises, for a first number of the IQ samples situated at a boundary between the first and the second OFDM symbol, transmitting, over the transmission link to a decoder of the base station system, the first number of IQ samples having a representation spanning a first amplitude range.

Abstract: Described is a method performed by an encoder of a base station system (100) of a wireless communication network, for handling a bit stream for transmission over a transmission link (165) between a remote unit (160) and a base unit (170) of the base station system. The remote unit is arranged to transmit wireless signals to and receive from mobile stations (180). The bit stream comprises a first OFDM symbol and a second OFDM symbol, each OFDM symbol comprising a number of consecutive IQ samples. The method comprises, for a first number of the IQ samples situated at a boundary between the first and the second OFDM symbol, transmitting, over the transmission link to a decoder of the base station system, the first number of IQ samples having a representation spanning a first amplitude range.

Abstract: Disclosed is a method performed by an IRU (210) of abase station system (200), the base station system comprising the IRU (210), a BBU (230) connected to the IRU (210), and a first RH (221) connected to the IRU (210) via a packet data network (240). The first RH (221) is arranged for wireless transmission in RF of a plurality of antenna carriers to UEs (250). The method comprises receiving, from the BBU (230), a plurality of first digital representations of the plurality of antenna carriers of the first RH (221), each first digital representation representing one antenna carrier, the plurality of first digital representations being received in a baseband frequency range, frequency multiplexing the plurality of first digital representations of the plurality of antenna carriers into a second digital representation over a first bandwidth, and transmitting the second digital representation to the first RH (221).

Abstract: Described is a method performed by an encoder of a base station system of a wireless communication network, for handling a data stream comprising a number of consecutive IQ samples for transmission over a transmission network between a remote unit and a base unit of the base station system. The remote unit is arranged to transmit wireless signals to and receive from mobile stations, each of the number of IQ samples comprising a first number of bits.

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: 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 method and arrangement is proposed for adaptively generating a target noise margin for use on a DSL transmission line. The method includes determining a first quantity representing a current noise power on the line using line parameter data relating to the transmission performance of the line, determining a second quantity representing a worst-case noise power on said line using previously obtained values of the line parameter data, calculating the difference between the first and second quantities to generate a difference value, setting a target noise margin as at least equal to said difference value, and providing the target noise margin for use on the line upon initialisation of the line. In a preferred embodiment, the line parameter data is the bit loading on the line and the first and second quantities are values of the average signal-to-noise ratio on the line derived from the bit loading data.

Abstract: The present invention relates to a method for managing transmission resources in a digital communication system comprising an access network, such as a DSL system, implementing resource management for minimization of cross-talk interference in a cable or cable binder of the access network comprising a number, N of lines. It comprises the steps of: determining, by means of calculating means, for a respective of said lines, a relevant line set, comprising interference relevant lines, for said respective line, and applying, for the respective line, an algorithm for resource management using the determined relevant line set, thus reducing computational complexity of the resource management algorithm.

Abstract: The present invention relates to a method and an arrangement based on two-port network (TPN) theory that allows analytically estimating the loop transfer function from open and short-circuited input impedance measurements, e.g. single ended line transmission (SELT) measurements, by utilizing the fact that the line under test (LUT) can be considered reciprocal and by assuming that the LUT is symmetric. Hence, by using the present invention and an estimation of the noise on the line, the attainable bit rate at the customer premises can be determined by means of SELT measurements at the CO. The transfer function of a telephone copper-loop is estimated regardless of its topology by impedance measurements from the CO side. Specifically, such estimation is carried out from the calculation of the transmission parameters of loop, which are expressed only in terms of open and short-circuited input impedance measurements at the CO when reciprocity and symmetry is assumed.

Abstract: A method of determining a number of operating points for spectrum management of a plurality of digital subscriber lines in a communications network, the method comprising the steps of: determining optimization criteria (Oi) for the digital subscriber lines; determining crosstalk gains (Gi) for the digital subscriber lines; determining an initial population (Pi) of operating points (x1, . . . , xZ) where each of the operating points comprises importance ratings for each digital subscriber line of the plurality of digital subscriber lines; calculating new values of crosstalk and power spectrum densities (S) for the digital subscriber lines, by executing spectrum balancing for each operating point until the optimization criteria are fulfilled; calculating a new population of operating points, by executing an evolutionary algorithm; and iteratively performing the steps of calculating until a predefined stopping criterion is fulfilled.

Abstract: A method and arrangement is proposed for adaptively generating a target noise margin for use on a DSL transmission line. The method includes determining a first quantity representing a current noise power on the line using line parameter data relating to the transmission performance of the line, determining a second quantity representing a worst-case noise power on said line using previously obtained values of the line parameter data, calculating the difference between the first and second quantities to generate a difference value, setting a target noise margin as at least equal to said difference value, and providing the target noise margin for use on the line upon initialisation of the line. In a preferred embodiment, the line parameter data is the bit loading on the line and the first and second quantities are values of the average signal-to-noise ratio on the line derived from the bit loading data.

Abstract: A method, central unit, and modem for reducing crosstalk in a Digital Subscriber Line (DSL) system. A virtual line referred to as a ghost line is introduced in the system as a substitution for all of the lines except a first line to induce crosstalk to the first line. The Power Spectral Density (PSD) on the first line is allocated to optimize against the ghost line. A modem on the first line reports to a central Spectrum Management Center (SMC), a measure indicating crosstalk impact from the ghost line. This process is repeated for each line. The SMC calculates updated ghost line parameters for each line, which reflect current crosstalk characteristics between each modem and the remaining modems, and sends the updated parameters to the modems. The modems then reallocate PSDs with respect to the updated ghost line parameters to either maximize the rate or minimize the power on their respective lines.

Abstract: A method and transmitter unit in a multi-tone multi-line based transmission system such as a digital subscriber line system for determining a Power Spectral Density (PSD) of a plurality of users over a physical channel for at least one tone. Each of the users has a minimum required data rate and a maximum allowed power. A Power Minimization Problem (PMP) is formulated mathematically introducing Lagrangian multipliers and by utilizing a dual decomposition approach for the objective function of the PMP in order to solve the PMP on a per-tone basis.

Abstract: A method of determining a number of operating points for spectrum management of a plurality of digital subscriber lines in a communications network, the method comprising the steps of: determining optimization criteria (Oi) for the digital subscriber lines; determining crosstalk gains (Gi) for the digital subscriber lines; determining an initial population (Pi) of operating points (x1, . . . , xZ) where each of the operating points comprises importance ratings for each digital subscriber line of the plurality of digital subscriber lines; calculating new values of crosstalk and power spectrum densities (S) for the digital subscriber lines, by executing spectrum balancing for each operating point until the optimization criteria are fulfilled; calculating a new population of operating points, by executing an evolutionary algorithm; and iteratively performing the steps of calculating until a predefined stopping criterion is fulfilled.