Showing papers by "Stefan Parkvall published in 2014"

5G wireless access: requirements and realization

Abstract: 5G, the mobile communication technology for beyond 2020, will provide access to information and the sharing of data anywhere and anytime for anyone and anything. This paper describes the current status of the processes moving toward 5G, or "IMT for 2020 and beyond," in ITU-R. We also provide a view of 5G opportunities, challenges, requirements and technical solutions.

5G radio access

Abstract: Mobile communication has evolved significantly from early voice systems to today's highly sophisticated integrated communication platforms that provide numerous services, and support countless applications used by billions of people around the world.

Device-to-Device Communications for National Security and Public Safety

Abstract: Device-to-device (D2D) communications have been proposed as an underlay to long-term evolution (LTE) networks as a means of harvesting the proximity, reuse, and hop gains. However, D2D communications can also serve as a technology component for providing public protection and disaster relief (PPDR) and national security and public safety (NSPS) services. In the United States, for example, spectrum has been reserved in the 700-MHz band for an LTE-based public safety network. The key requirement for the evolving broadband PPDR and NSPS services capable systems is to provide access to cellular services when the infrastructure is available and to efficiently support local services even if a subset or all of the network nodes become dysfunctional due to public disaster or emergency situations. This paper reviews some of the key requirements, technology challenges, and solution approaches that must be in place in order to enable LTE networks and, in particular, D2D communications, to meet PPDR and NSPS-related requirements. In particular, we propose a clustering-procedure-based approach to the design of a system that integrates cellular and ad hoc operation modes depending on the availability of infrastructure nodes. System simulations demonstrate the viability of the proposed design. The proposed scheme is currently considered as a technology component of the evolving 5G concept developed by the European 5G research project METIS.

System and method for beam-based physical random-access

Abstract: A method in a wireless device for performing random access to a network node. The method comprises receiving a set of downlink beam-specific reference signals, BRS, from the network node, and determining a preferred BRS based on the received signal power for each BRS. The method also comprises selecting, based on the preferred BRS, a random-access resource to be used for transmitting a random-access attempt to the network node, as well as using the selected random-access resource when transmitting a random-access attempt to the network node, whereby the selection of random-access resource indicates to the network node which downlink beam is preferred by the wireless device to be used for downlink transmissions.

Wireless device, network node, methods therein, for respectively sending and receiving a report on quality of transmitted beams

Abstract: Embodiments herein relate to a method performed by a wireless device (850) for sending a report on channel information to a network node; a method performed by a network node (830) for receiving a report on channel information; a wireless device (850) and a network node (830).The network node (830) controls at least one Transmission Point (TP) that transmits TP beams. Each TP beam is associated with respective beamformed Beam-specific Reference Signal (BRS) for channel information measurements. The wireless device (850) sends the report, which comprises a number of sub-reports, to the network node (830). Each sub-report is associated with a TP beam. Each associated TP beam comprises at least one BRS and is selected by the device (830).. Each sub-report is also associated with an indicator of channel quality value for one code word transmitted by the network node (850) on the associated TP beam. Publ. Figure 17

Uplink multi-tti scheduling in tdd system

Abstract: Systems and methods are disclosed for transmission and reception of an uplink grant during a gap created in radio resources assigned by a previous multiple Transmit Time Interval (multi-TTI) uplink grant in a system operating according to a Time Division Duplexing (TDD) scheme. In one embodiment, a method of operation of a radio network node in a cellular communications network is provided. The method includes transmitting a first uplink grant that assigns radio resources for a multi-TTI uplink transmission, and transmitting a second uplink grant during a gap in the radio resources assigned by the first uplink grant. In one embodiment, by utilizing the gap to transmit the second uplink grant, uplink radio resources assigned for uplink transmission can be maximized, which is particularly beneficial in high uplink traffic conditions.

A method and wireless device for providing device-to-device communication

Abstract: The present disclosure relates to methods and to a wireless device, 10, 20, for enabling device-to-device communication. In particular the present disclosure relates to a method, performed in a radio node, of assigning resources for direct control signalling. The method comprises receiving, S1, from at least one further radio node, 160, sets of resources for direct control signalling in a respective cell or cluster. The method further comprises assigning, S2, resources for direct control signalling transmission within an area controlled by the radio node based at least on the received sets of resources, and transmitting, S3, to wireless devices controlled by the radio node, a message indicating resources assigned for direct control signalling. The disclosure also relates to the corresponding method in a wireless device and to a radio and to a wireless device implementing the methods, as well as to corresponding computer programs.

Enhanced PRACH preamble format

Abstract: The present invention relates to a user terminal, UE, in a wireless communication system (1). The user terminal (4a, 4b) comprisesa receiver unit(5a, 5b), a transmitter unit(6a, 6b) configured to transmit data in transmit sub-frames occurring at defined sub-frameintervals, and a control unit(7a, 7b) configured to control the receiver circuit (5a, 5b) andthetransmitter circuit (6a, 6b).The control unit(7a, 7b) is alsoconfigured tocreate a PRACH, Physical Random-Access Channel, preamble (27) as an uplink transmission to a node (2) that is arranged to receive communication from the user terminal in said sub-frames. This communication comprises OFDM, Orthogonal Frequency-Division Multiplexing, based symbols (20). The control unit(7a, 7b)is configured to create each PRACH preamble (27) such that is comprises a sequence of a plurality of identical random access sequences (s(n)), where each random access sequence (s(n)) has the same length in time as each one of the OFDM based symbols (20a, 20b, 20c). The present invention also relates to a corresponding method.

Processing of Random Access Preamble Sequences

Abstract: The present disclosure relates to random access in wireless communication systems, and in particular to a wireless device, a preamble receiver, and methods for processing random access preamble signals. A disclosed method in a wireless device comprises generating (S11) one or more identical short sequences having a same time duration as an OFDM symbol used for carrying data traffic in a radio access network of the wireless device. The method also comprises generating (S12) at least one offset indicator sequence different from each of the short sequences, and constructing (S13) the preamble sequence by concatenating the at least one offset indicator sequence and the one or more identical short sequences in time, such that each of the at least one offset indicator sequence has a respective pre-determined location in the preamble sequence.

Preamble sets matched to uplink transmission conditions

Abstract: The present disclosure relates to random access in wireless communication systems, and in particular to transmitting, receiving, and detecting preamble sequences A method in a wireless device for transmitting a preamble sequence to a network node is disclosed The method comprises configuring (S12) a number of preamble sequences into two or more preamble sets, wherein each preamble set is associated with at least one respective uplink transmission condition; determining (S13) a transmission condition of an uplink from the wireless device to the network node; and selecting (S14) one out of the two or more preamble sets based on the determined transmission condition to be a selected preamble set, and a preamble sequence from the selected preamble set to be a selected preamble sequence; as well as transmitting (S15) the selected preamble sequence on the uplink

Conditional Uplink Radio Resource Utilization in a Cellular Network

Abstract: A communication device (10) receives an uplink grant from a node (100) of a cellular network. The uplink grant indicates uplink radio resources allocated to the communication device (10) in reoccurring time intervals. For each of these time intervals, the communication device (10) selects between an active mode and an inactive mode. In the active mode the communication device (10) performs an uplink transmission in the allocated uplink radio resources. In the inactive mode the communication device (10) performs no uplink transmission in the allocated uplink radio resources.

Robust transmission on downlink discontinuous transmission carrier

Abstract: A method and system for downlink discontinuous transmission are provided. In one embodiment, a base station includes a memory, a processor and a transmitter. The memory stores information to be transmitted in a subset of sub frames to a UE. The information includes transmission mode configuration information. The processor operates to configure the transmitter according to a selected transmission mode configuration that includes one of a transmit diversity mode and a MIMO mode, and configures the transmitter to transmit discontinuously and include CRS in only a subset of sub frames.

5G Wireless Access - Trial Concept and Results

Abstract: 5G is the next step in the evolution of mobile communication and a key component of the future networked society. With capabilities such as massive system capacity, higher data rates, very low latency and ultra-high reliability, 5G will provide significantly enhanced mobile-broadband experience but also support a wide range of new wireless applications and use cases. In this paper, a trial system for 5G mobile broadband operating at 15 GHz is outlined, together with initial experimental results showing that data rates of many Gbit/s are possible.

Advanced antenna solutions for 5G wireless access

Abstract: The use of multiple transmit antennas at the base station and device side play an important role already in current 4G/LTE systems, enhancing system performance and extending the data rates that can be provided to the end user. For the future (5G) wireless-access solution advanced antenna solutions are expected to play an even more pronounced role. 5G wireless access needs to provide substantially higher data rates, up to the multi-Gbps range in specific scenarios and with hundreds of Mbps to be generally available in urban/suburban environments, as well as handle traffic volumes hundreds of times higher than today. Advanced multi-antenna transmission will be key to fulfill both these requirements. At the same time, 5G wireless is expected to extend to frequency-range-of-operation beyond 10 GHz and into the mmw range. The corresponding smaller wave length will be an enabler of more advanced antenna configurations with a much larger number of controllable antenna elements compared to the antenna configurations of today. In this paper we discuss advanced antenna solutions for 5G wireless access, what are the opportunities, alternatives, and possible obstacles.

A user equipment, a network node and methods therein for performing and enabling device-to-device (d2d) communication in a radio communications network

Abstract: A method performed by a first user equipment (121) for performing Device-to- Device, D2D, communications with a second user equipment (122)is provided. The first user equipment (121) determines that a valid timing reference is not present in the first user equipment (121). Also,the first user equipment (121) determines whether a preconfigured timing advance can be used in the D2D communication. Then, when determined that the preconfigured timing advance can be used, the first user equipment (121) transmits a D2D signal to the second user equipment (122) with a timing using the preconfigured timing advance to perform D2D communication. A user equipment (121), a network node (110)and method therein for enabling D2D communications between user equipments (121, 122) in a radio communications network (100) are also provided.

Scheduling in wireless backhaul networks

Abstract: There is provided scheduling in a wireless backhaul network providing backhaul to an end-user access network. The wireless backhaul network comprises a hub node and a client node providing backhaul to at least one radio base station in the end-user access network. Scheduling information of the at least one radio base station is acquired. Based on the scheduling information a scheduling of a first wireless link of two consecutive wireless links, one of which being a wireless link between the hub node and the client node, is determined, wherein the scheduling is based on scheduling information of a second wireless link of the two consecutive wireless links. The scheduling is provided to at least one of the hub node and the client node.

Method and arrangement in a radio-access network

Abstract: The invention relates to a method and arrangement for transmitting and receiving control information in a radio-access network. A network node transmits first control information in a first part and second control information in a second part of a time-frequency region that is transmitted after a control region in a subframe. The second part is located later in the subframe than the first part. The second control information may be less time-critical than the first control information. An intermediate node receives and decodes the first control information at the end of the first part. When the first control information indicates that the subframe comprises data payload to the intermediate node, the intermediate node receives and decodes the data payload. The intermediate node receives second control information at the end of the second part.

Methods and Apparatuses for Enabling a Wireless Device to Communicate with a Radio Network Node in an Unlicensed Spectrum

Abstract: It is disclosed a wireless device ( 302, 90, 100 ), a radio network node ( 304, 70, 80 ) and methods therefore, for communicating in a network. The wireless device is configured to determine ( 52, 306 ) one or more possible first sequences of a discovery signal. The wireless device is configured to receive ( 54, 310 ) a second sequence of the discovery signal, and to determine ( 56, 312 ) if the one or more possible first sequences match the second sequence.

Radio resource allocation of unlicensed frequency bands

Abstract: A network node operates in accordance with a first radio access technology in a frequency band, wherein communication according to a second radio access technology may occupy one or more of the radio resources of the frequency band. A method comprises receiving a beacon signal associated with the second radio access technology and determining whether or not the beacon signal comprises information indicative of which of the radio resources of the frequency band are used as primary and secondary channels, respectively, in accordance with the second radio access technology. The method also comprises determining a communication activity rate of at least one of the radio resources of the frequency band and selecting one or more of the radio resources of the frequency band based on the determined communication activity rate, and allocating one or more of the selected radio resources to communication in accordance with the first radio access technology.

A wireless device, a network node and methods therein for reporting channel state information (csi) in a radio communications network

Abstract: A method performed by a wireless device (121, 122) for determining Channel State Information, CSI, estimates to be transmitted in a CSI report for at least one CSI process configured for the wireless device (121, 122) to a network node (110) in a radio communications network (100) is provided The wireless device (121, 122) receives a message comprising an indication to discard existing CSI estimates and/or an indication to use CSI estimates corresponding to a determined period of time In response to said message, the wireless device (121, 122) determines CSI estimates to be used in the CSI report to the network node (110) according to the received indication A wireless device (121, 122) is also described Furthermore, a network node (110) and method therein for controlling CSI estimates transmitted by one or more wireless devices (121, 122) in CSI reports of at least one CSI process configured for the one or more wireless devices (121, 122) to the network node (110) in a radio communications network (100) are also provided

Radio devices and methods for performing communication via licensed and unlicensed spectrum

Abstract: A first and a second radio communication device and a respective method performed thereby for communicating between the first and the second radio communication device are provided. The method in the first radio communication device comprises transmitting, on an unlicensed frequency band, to at least the second radio communication device, an indication of a duration of a guard period, wherein an upcoming data transmission is to be performed to the second radio communication device after the expiration of the guard period. The method further comprises during the guard period, sending and/or receiving information to/from at least one other radio communication device, the other communication device being the second radio communication device or a third communication device.

Small bandwidth cell configuration, for reducing interference with overlapping large bandwidth cell

Abstract: A method is disclosed of a network node of a cellular communication system for configuring a first cell of the cellular communication system in relation to a second cell of the cellular communication system. A coverage area of the first cell and a coverage area of the second cell overlap, at least partly. The first cell is to be provided by a first base station of the cellular communication system and has a first bandwidth and the second cell is provided by a second base station of the cellular communication system and has a second bandwidth which is larger than the first bandwidth. The method comprises determining an offset between a first carrier frequency of the first cell and a second carrier frequency of the second cell and configuring the first base station to provide the first cell based on the first carrier frequency. A first spectrum range defined by the first carrier frequency and the first bandwidth is comprised within a second spectrum range defined by the second carrier frequency and the second bandwidth. The offset is determined such that control signaling of the second cell is aligned with control signaling of the first cell to reduce an impact of interference between the control signaling of the first cell and the control signaling of the second cell. Corresponding computer program product, arrangement and network node are also disclosed.

Soft Cell Inter-Layer Interference Handling

Abstract: In a heterogeneous cell deployment a mobile terminal may need to receive control data transmissions from a macro node at the same time as a pico node is transmitting user data for the mobile terminal, using the same frequency or set of frequencies This can result in a problematic interference situation According to several embodiments of the present invention, at least one of two general approaches is used to mitigate the interference situation described above In a first approach, the pico node's transmission power is reduced in some time intervals, thereby reducing the interference to a level where reception from the macro node is possible In a second approach, which may be combined with the first approach in some cases, the data transmitted from the macro node is provided by the pico node, either alone or in combination with the macro node

Uplink resource scheduling in multiple time instances

Abstract: It is disclosed a network node (50; 60; 70), a communication device (80; 90; 100) and methods therein, for scheduling of uplink resources in multiple time instances and transmitting in accordance with the scheduled UL resources. By including (22) an indicator in an UL grant comprising an UL resource allocation, the indicator indicates that, for at least one UL time instance of the multiple time instances, at least one UL resource is excluded from, or added to, the UL resource allocation of the UL grant.

Random access preamble format for systems with many antennas

Abstract: The computational complexity of FFT (Fast Fourier Transform) processing in an OFDM (Orthogonal Frequency Division Multiplex) based receiver is large with a large amount of receiver antennas. In LTE (Long Term Evolution) release 8, FFTs of different size are used for user data and random-access preambles [1] requiring additional FFTs to be implemented for random-access reception. Within the current paper, a 5G random-access preamble format is proposed based on a short sequence of the same length as the length of the OFDM symbols that are used for other uplink physical channels, such as user data, control signaling, and reference signals. The preamble sequence is constructed by repeating the short sequence multiple times. A corresponding preamble detector in which FFTs of the same size as for other uplink channels and signals are used is also described. In this way, the amount of special random-access related processing and hardware support is significantly reduced for multi-antenna systems with frequency-domain beamforming. This preamble detector is also robust against inter-carrier interference from other uplink channels and signals. Furthermore, the proposed preamble detector scheme can be used in 5G scenarios with a high amount of phase noise and frequency errors. For time-domain beamforming, the beamforming weights can be changed during preamble reception such that the number of spatial directions is increased for which preamble detection is done. Simulation results are used to compare preamble formats for different lengths of the sequences.

Scheduling and Rate Adaptation

Abstract: This chapter discusses the key radio-resource-management functionality relevant for LTE, including downlink and uplink scheduling and reporting of channel-state information.

Method and devices for providing feedback in a communication system

Abstract: The disclosure relates to a method 20 of providing feedback performed in a receiving device 8. The receiving device 8 is capable of wireless communication with a transmitting device 12, 5. The method 20 comprises: receiving 21, from the transmitting device 12, 5, an encoded message block 10, the message block 10 comprising a number N of sub-blocks, S 1 ,..., S N ; decoding 22 the received N sub-blocks, S 1 ,..., S N ; detecting 23 at least one and less than N sub-blocks being erroneously decoded; and providing 24 feedback information to the transmitting node 5, the feedback information indicating the at least one and less than N sub-blocks detected as erroneously decoded sub-blocks. The disclosure also relates to corresponding method in a transmitting device, to receiving device, transmitting device, computer programs and computer program products.

Full duplex in a wireless communication network

Abstract: There is provided a method performed by a wireless node (10; 10') for determining when to use full duplex in the wireless node for communicating in a wireless communication network. The method comprises the step of estimating (S10) an influence on neighbouring wireless nodes (20; 20', 30; 30') of using full duplex in the wireless node (10; 10'). The method further comprises the step of deciding (S20) whether to use full duplex in the wireless node (10; 10') or not, based on the estimated influence.

Control of wireless communication node power consumption

Abstract: FIELD: physics, communication.SUBSTANCE: invention relates to control of power consumption of a wireless communication node, such as a base communication station. The technical result is achieved by the fact that the device for control of power consumption of a network node connected to a cell includes a monitor of terminal activity configured as capable of detecting active terminals serviced by a cell, and a transmission controller, which is connected to a terminal activity monitor and is configured to limit transmission of information along a downlink into the cell during periods of time, when there are no active terminals serviced by the cell. During these periods the transmission is limited by interrupted information transfer that helps to active terminals not serviced by the cell in case of cell detection.EFFECT: reduction of power amount consumed by a wireless network node.14 cl, 11 dwg